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Tuesday, February 20, 2018

February 20, 2018 Kim’s Weekly Garden Blog

Hi Gardeners
Snowdrops
I found some snowdrops in bloom today! It’s 60 degrees here today and raining but during a lull in the rain Gizzy and I went out to tour the yard.  I looked yesterday when it was 45 degrees and didn’t find them but today there they were, little white flowers just beginning to open.  They are in bloom on exactly the same day as last year, when I took the picture.
I see crocus shoots and even some tulips coming up too.  The next mild day it isn’t raining I need to get out there and rake the lousy black walnuts off the beds.  There’s so many they’ll keep things from poking through.  We had a huge crop of walnuts last fall, where are the squirrels when you need them?
I keep saying I’d like to get someone to cut that walnut tree down but I don’t because, well, it’s a healthy tree and it does form the shade for my shade garden.  But those walnut trees are a big messy pain.
I hurried inside to check my notes on where I planted the new bulbs last fall.  I love it when the new things bloom in the spring.  I love the old things that bloom too.
There’s been a small possum hiding in a muck tub in the barn the last few days.  There was a little bit of waste paper in there, enough to make a cozy bed I guess, right close to where I feed the cats.  It’s just a small thing and I don’t mind possums so I have left him alone.  He’ll probably move along soon.  Maybe he doesn’t like mud.
The chickens have been out scratching, we went from 70% snow covered ground to almost no snow in one day.  The lower part of the yard to the east is flooded and there is mud everywhere.  Its gray and damp but I am still happy because February is almost over and spring is almost here and the first flowers have just bloomed.  Yeah!

When to start seeds- zone 6 and lower

This time of year, late February, when the sun and our urge to plant is getting stronger, it can be tempting to novice and experienced gardeners alike to start some seeds. For gardeners in zones 7 and above you can probably plant most things inside and some things outside now.  But if you live in planting zones 6 and lower and don’t have a heated greenhouse some restraint is still needed.  (Find your planting zone here.  http://planthardiness.ars.usda.gov/PHZMWeb/  ).

Even if you have a greenhouse or a good grow light set up there’s a good reason not to start plants too soon before you can plant them outside.  Plants inside too long tend to get root bound, leggy and stressed.  They have more chances to get disease and pest problems.  The more mature a plant is when it’s transplanted to the garden the more stressed it’s likely to be.  Unless you have good greenhouse type conditions you don’t want most plants to start blooming inside.  Many times a small, stocky plant planted in the ground at the same time as an older, larger plant of the same type will soon overtake the older plant in growth and production.

For most annual flowers and vegetables, you’ll want to plant them outside after the last frost.  (A few things can be planted outside before the last frost if they are hardened off.)  If you start your plants too early your chances of success will be lower. Most seed packets or the descriptions of plants in catalogs will give you a “weeks before last frost to start” figure.  If you don’t find it, you’ll have to look up the plant in references or check the lists below.  You’ll need to find out what the date of your last frost generally is.  For this ask your County extension office or some experienced gardeners in your area.

When looking at last frost charts pay attention to the charts explanatory information.  For example, some charts list the mean probability of the last frost.  Using this date, you have a 50/50 chance of a frost on that date.  That’s not such great odds for a gardener. You’ll want to use a date that gives you at least a 90% probability that the last frost will have passed.  Then count back to find the proper time to start seeds inside.  

Seeds to be started in January and February in zones 5 and 6 include; begonias of all types from seed, impatiens, coleus, geraniums, petunias, and lisianthus. Also tuberous begonia bulbs, calla lily, banana and elephant ear bulbs can be started in pots.  Start pansy and viola seeds early because they can be planted outside quite early, before the last frost.  If you are in zone 4 and lower late February is probably best.

Pansies can go outside before the last frost
In March, in zones 5-6, most types of perennial and bi-annual and some annual flower seeds can be started.  Start celosia, diascia, marigolds, nicotiana, snapdragons, salvia, verbena, perennial herb seeds, onions from seed, and celery.  If you have a heated green house a few early tomatoes and peppers can be started, don’t start your whole crop this early.   March is a good month to root cuttings from over wintered coleus, impatiens, geraniums and begonias.  Zone 4 and lower gardeners should wait until early April to start most of these.
In April in zone 5-6 start tomatoes, peppers, eggplant, cabbage, broccoli, Brussels sprouts, alyssum, cosmos, zinnias, calendula, cleome, sunflowers, head lettuce, basil, cilantro, ornamental kale and cabbages. Pot up canna and dahlia bulbs for a head start.  In April peas and leaf lettuce can be planted directly in the garden.  In most zone 6 areas radishes, carrots, beets, set onions and potatoes can also be planted in the garden.
In zones 4 and lower the above plants shouldn’t be planted until late April-early May inside and you’ll have to wait to plant those outside varieties until early May at least.
In May in zones 5-6 you can start: morning glories and moon flower vines, hyacinth bean, nasturtiums, cucumbers, squash, melons, beans and corn (for those who like transplants instead of direct seeding in the garden).  By early May most 5-6 zone areas can plant radish, beets, carrots, potatoes and set onions directly in the garden.  In late May - early June plant sweet and pop corn, beans, squash, melons, cucumbers, sunflowers directly in the garden.  Zone 4 and lower gardeners should use early to mid-June for planting outside and about mid-May for starting the above-mentioned plants inside.
The above dates are for guidance.  Before setting a date for planting outside you’ll need to also consider the current years weather conditions. Look ahead at the 10-day forecast and see if any below 40 degree lows are predicted.  If they are, wait to transplant tender plants or plant seeds of the frost tender plants in the ground until the weather has passed. 
Gardeners should also be aware of micro-climates.  A micro-climate means a small area like your garden may have different growing conditions than the area at large.  If you are in a low spot, you may have what is called a frost pocket, where frost may occur even when neighbors don’t get one.  A sheltered area against something that reflects heat, like a white wall, may be warmer than the surrounding area.
Soil temperature can also affect when to transplant or plant seed outside.  You can measure soil temperature with a regular thermometer stuck about 6 inches into the ground but a soil thermometer is better. A quick change in the weather may not have allowed soil to warm very well and soil under heavy mulch will also be colder. Beets, leaf lettuce, and peas can be planted when soil temperature is about 45 degrees F, peas can take it even colder soils. At 60 degrees F soil temperature carrots, head lettuce, spinach, set onions, potatoes, cabbage, broccoli, and most annual flower seed can be planted as seeds or transplants. 
Wait until the soil has warmed to above 70 degrees to plant beans, corn, squash, cucumbers, pumpkins in the ground and to transplant those plants and tomatoes, eggplants and peppers into the soil, providing frost danger has also passed.
Those pots of tender bulbs you started inside, calla, begonia, dahlia, glads, canna and so on should not be put outside until after all danger of frost has passed.
What about all those natural signs and planting by the moon?  If you are familiar with the area after having gardened there for many years you may know when it’s right to plant certain things by what other natural phenomena you are observing in your area.  For example, I know when the lilacs are in full bloom it’s generally safe to plant my tomatoes outside.  When forsythia blooms here it’s time to plant leaf lettuce and peas.  That may not hold true for your area though, even in the same planting zone.  An experienced gardener in the area may guide you here or you’ll just gave to keep records and find out yourself.
Planting by the moon is just old wives’ tales.  There’s no evidence that whatever phase the moon is in when you plant will affect how your seeds germinate and grow.  I do want to add one thing about the moon here.  It’s been my experience, and I don’t have any thing but my own records to back this up, that there is generally a frost around the full moon in May.  Last year the May full moon was on the 10th and we had a hard frost on the 9th but no frost after that. That’s bad news this year because the full moon is not until the 29th of May.  If you are further south in zone 7 your last frost may be near the full moon in April, this year it’s April 29th  so you are likely to be safe. But don’t bet on this until you’ve kept records for a few years.
If the weather is unusually warm earlier than normal it’s tempting to try to get an early start outside. Look ahead at the weather forecast and if it looks good plant half your plants/seeds and hold back some.  If the weather shifts back to a more normal pattern, you won’t lose everything.  You can protect plants from frost with coverings, but cold weather may still set them back and a freeze will kill them.  Sometimes you’ll get lucky and get an early harvest. But it’s generally better to be a little late planting than too early.
I have several more articles about starting seeds, seed requirements and so on to the right of this blog.  You can also click here; http://gardeninggrannysgardenpages.blogspot.com/p/seeds-germination.html
  
Growing pawpaw, Asimina triloba

The paw-paw or Michigan banana or Hoosier banana or a whole bunch of other common names generally using the word banana in them, is a small tree native to North America. The fruits of the tree somewhat resemble fat bananas. Paw-paw is also a common name for papaya and another tropical fruit and it’s extremely important when reading things like herbals that you know exactly which plant they are referring to since confusing the plants might be deadly.

Many people are unaware of this native fruit tree that produces large delicious fruit, although that fruit has become a bit controversial.  When the Spanish began exploring the interior of the North American continent they reported on the fruit (1541) and that indigenous people seemed to be cultivating it in places. George Washington and Thomas Jefferson were both quite fond of the fruit and grew the trees on their plantations.

The paw-paw tree makes a nice, somewhat tropical looking specimen tree and when it’s needs are met it produces a crop of large, tasty fruit with a custard-like interior that have the taste of banana and cantaloupe mixed. The trees are resistant to deer, insect and disease damage.  The fruit does not store or ship well though, so it’s never became a commercial crop, although with the current interest in unusual and local foods there are people exploring that idea. It is a good backyard fruit tree for some gardeners.  But before you rush out and buy a half dozen paw-paw trees there are some things you need to know and think about.  Keep reading.


Paw-paw description

The paw-paw is a small tree, to about 35 feet high, that is native to the eastern half of the North American from southern Canada down through northern Florida although it does not grow naturally close to the coast.  The paw-paw prefers moist shaded woodland edges and rich river bottoms.  The trees put out suckers or clones and often grow as a thicket of genetically identical small trees.

The leaves of paw-paw are long pointed ovals, 10-12 inches long and 4-5 inches wide.  They appear at the ends of the branches arranged in a symmetrical spiral around the twig.  The veins and mid-rib are prominent.  When young the leaves are somewhat hairy with a rusty tinge beneath. When mature they are smooth and glossy deep green with a slightly drooping habit.  If you crush a leaf it has an unpleasant smell that reminds me of the nightshade family.  The leaves turn a rich rust tinged gold in the fall.

paw-paw leaves
The tree has a light gray bark that’s sometimes marked with paler blotches or small bumps.  There is a tough, fibrous inner bark that Native Americans had many uses for, they made nets, matts and ropes from it.  There is some speculation the trees may have been cultivated for that use as well as the fruit.  The wood of a paw-paw is light yellow and spongey. Like the leaves damaged bark has an unpleasant smell.

Paw-paws bloom in early spring, before the leaves have expanded very much. The 2-inch flowers of paw-paw are marron or purplish red and bell shaped, facing downward or to the side.  They have both sex parts, but like the apple, they are not self-fertile. Paw-paw flowers also have a bad smell, although they are not as smelly as gingkoes.  They smell like dead meat and the pollinators are flies and beetles.
Paw paw flowers
Wikipedia

Paw-paws are said to need cross pollination with another paw-paw that is not closely related and those who want to grow them for fruit should plant two varieties of trees fairly close together.  The paw-paws in those stands of clonal trees probably don’t pollinate each other because they are identical genetically.  However, there is some controversy about this.  People claim to hand pollinate their paw-paws by moving pollen from one flower on the tree to the next and get fruit.  It’s possible that like apples, some paw-paw trees may have a genetic adaptation that allows some individual trees to produce fruit when helped with pollination.  A flower can’t pollinate itself because the male and female parts of each flower mature at different times.

Paw-paw fruit is oblong and plump, and often occurs in clusters of up to 3 fruits fused at the base.  Fruits are green when immature, ripening to brownish yellow in early fall.  When ripe the flesh of the fruit is pleasant smelling, unlike the rest of the tree.  Unlike a banana you can’t peel back outer skin. The ripe fruit is soft inside and yellow and is generally scooped off the rind for use.  There are numerous dark brown, hard shelled seeds inside about the size of a bean.

A caution here I’ll go into more deeply later. Many people are allergic to paw-paw fruit.  It can cause a rash if handled or if eaten it can cause hives and severe vomiting if you are allergic.  Use caution when consuming your first paw-paw fruit.  Cooking the fruit seems to intensify, not lessen reactions.

Paw-paw fruit
wikipedia

Cultivation of the paw-paw

Paw-paws are winter hardy to zone 5. They like rich loamy, moist but not saturated soil.  They tolerate pH variations from mildly acidic to mildly alkaline – about pH 6-8.  Plant paw-paws where you can irrigate them when dry, especially when they are young.

Paw-paws can be tricky to establish.  In nature the seeds drop down on the ground to sprout or suckers pop up under tall grasses, weeds and shrubs.  It takes several years for the young tree to reach above the undergrowth and receive direct sunlight.  At that point they can handle direct sunlight if the soil is moist and more fruit is produced in full sun.  But young paw-paw trees must never be placed in full sun situations, they quickly die. Adult trees will also do well in partial shade, particularly in the south.

Paw-paws greatly resent transplanting, the roots are quite fragile.  So it can be difficult for the gardener to place the tree where it’s shaded when young but will get more sun when it is older.  Most people get around this by providing artificial shade and lots of moisture for young trees and gradually reducing the shade or allowing the tree to grow out of it. Don’t keep the tree in a pot for long either, it will have a harder time adjusting after transplanting into the ground.

I used tree tubes to get my paw-paws growing.  The sides are translucent, and I put fine black netting over the top, which was removed when the plants reached the top of the 4 feet tube.  When the trees were a few feet over the tube top I removed that.  Shade cloth t-pees are sometimes used.

My paw-paw outgrowing a tree tube.

It is always best to buy small, potted paw-paw plants rather than bare root plants.  The best time to plant them is early spring while they are dormant, and moisture is abundant.  Larger trees- more that 3-4 feet high are extremely difficult to establish. Digging paw-paws from the wild is also hard to do successfully, a large root ball must be removed around the roots of small trees and the tree re-planted immediately.  Rooting cuttings of paw-paw is only rarely successful.

Paw-paws can be started from seed.  The seed must have a cold stratification period to sprout.  That means keeping the seeds in a moist pot of soil in temperatures about 35 degrees for at least 9 weeks.  Seeds don’t store more than a year and maintain good germination rates and they must not be allowed to dry out too much in storage. It takes 6-8 years for a paw-paw to produce it’s first flowers when grown from seed.

Gardeners should remember that paw-paws need 2 varieties to produce fruit.  There are many commercial varieties now;  'Allegheny', 'Mango', 'Mitchell', ‘Overleese’, 'Potomac', 'Prolific', 'Rappahannock', 'Shenandoah', 'Sunflower', 'Taylor',  'Wabash', ‘Wells’ and ‘Zimmerman’ are some cultivars. Some are better for a certain area than others. Ask your County Extension office if they can recommend varieties.

Paw paws don’t need much fertilization.  For the first 2 years after planting don’t fertilize at all.  Once the trees are old enough to bloom a fruit tree fertilizer applied as the label directs can be added in early spring when you see buds and again in late spring-early summer if you see fruit forming.  Don’t fertilize paw-paws in late summer or fall as it tends to cause new growth that will not harden off before winter.

Paw-paws don’t need much pruning either.  Fruit develops on new growth so a light pruning when the plant is dormant can stimulate more fruit production.  Remove unruly branches to shape the tree, and crossing and rubbing branches.  You may want to remove any sucker trees that pop up around the original tree if you don’t want a thicket developing.

Fruit from the paw-paw is ready to harvest when it is deep yellow brown and soft.  It will slip easily off the tree.  Paw-paw fruit does not store well, a day or two at room temperature and a little longer in the fridge.  The flesh can be frozen and the fruit is sometimes turned into jam.

That disagreeable smell of paw-paw leaves and stems is from toxins called acetogenins.  Because of the toxins paw-paws are rarely bothered by insects or even animal pests.  One pest that can handle the toxins is Asimina Webworm Moth (Omphalocera munroei) caterpillarsIt looks a lot like other webworms, it’s a brown caterpillar with a black stripe up the middle and little white spots.  It makes a fine web on leaves, pulling them together for shelter.  It’s uncommon and rarely severely damages the tree.

Another caterpillar, that of the zebra swallowtail butterfly (Protographium marcellus), uses paw-paw as a larval food.  The toxins in the leaves protect the caterpillars from predation.  These caterpillars do not cause any major problem for the trees.

Usually deer and rabbits don’t bother the trees.  However, I had a tree damaged by deer browsing one winter so the rule doesn’t always hold true.  Others have said goats and mules will eat the trees.  Maybe they get a whopping stomach ache and never do it again.

Uses and cautions for paw-paw

Yes, the fruit can be eaten, and paw-paw plant parts were once used medicinally in various ways.  However, paw-paws also contain some very potent toxins.  A natural pesticide made from paw-paw twigs is being tested and it seems to be quite effective.  But before you experiment you should know that natural does not mean safe.  This pesticide is not selective, it kills good and bad insects and it may affect other animals such as birds and earthworms.  Humans handling it need to be very careful and wear protective clothing.  It remains to be seen if the product will pass EPA tests.

Recently research has found that paw-paw fruit has a high concentration of annonacin, a chemical that causes damage to the nervous system.  A tropical relative of paw-paw, Annona muricata (soursop or graviola), which also has high amounts of annonacin, is known to cause a Parkinson-like disease in those who consume a lot of the fruit or use parts of the plants for medicine.

Many people are allergic to paw-paw fruit. But it is also thought that eating more than one or two fruits at a time in those not allergic may cause gastrointestinal problems.  Baking the paw-paw in bread or otherwise cooking it seems to increase digestive problems.  The fruit is best consumed raw. The seeds should not be swallowed.  They are high in toxins and while most would pass through the digestive system, if they didn’t they might cause neurological damage as well as other problems.

Many people love the sweet flavor of paw-paw fruit but it’s a food that should be savored in small quantities. There are lots of anecdotes about people becoming very ill after pigging out on the fruit.  Use care the first time you eat the fruit; an allergic reaction may cause vomiting or more severe symptoms.

It is thought that native people may have cultivated varieties of paw-paw that had fewer toxins than others.  We’ll never know. Perhaps they just knew the limits to consuming and using paw-paw. Plant breeders are trying to see if the annonacin levels can be reduced by selective breeding.

There are old herbal remedies for many parts of the paw-paw. However only the most experienced herbalists should experiment with the paw-paw because of it’s toxins. Do not consume home remedies containing twigs, leaves, roots or bark that you find in old books, some of these are actually made with different species of plants called paw-paw as mentioned before. Even if they are for American paw-paw they could be very dangerous. 

Paw-paw is thought to be safe when used topically- a recent research study found a mixture of pawpaw, thymol, and tea tree oil was found to be quite effective in killing head lice.  Paw-paw may be used to treat wounds but once again beware of an allergic reaction such as rash or hives.

There are some research studies being done using various paw-paw extracts to destroy tumors and other types of cancers.  These use carefully calibrated standardized doses and are generally injected.  Do not experiment on yourself.
Despite some drawbacks paw-paws make lovely trees for the landscape and if you are lucky you’ll get to enjoy some unusual fruit.  Plant a couple and just enjoy them.

Free Master Gardener lesson 3- the shoots

Last week we discussed plant cells and tissues.  This week we’ll discuss plant organs and the organ system the above ground organs belong to- shoots.  Shoots are the plant organ system that includes leaves, stems and flowers.  Because I want to keep these articles short I am just going to discuss leaves and stems this weeks and flowers, which are very interesting and complex, and fruit next week.  And after that I’ll talk about the roots, the second organ system.

Leaves are valuable not only to plants but to all animal life on earth. They are the most important organs on earth, without them animal life would cease to exist.  Leaves are the main areas where photosynthesis, the catalyst for life on earth, takes place.  Photosynthesis creates food – the basis of all animal food systems – from light and water in those little chloroplasts that are in plant cells.  As a waste product of food production plant cells release oxygen, which is also critical for animal life on earth. 

Leaves are so vital to life on earth, yet many people don’t know or don’t care much about them.  We munch them in salads, drink tea made from them, and choose plants with pretty ones for our gardens.  We curse as we rake them from the lawn and smoke them to get high.  It’s time everyone knew more about leaves.
 
Sedums have very small leaves
Leaves range from bitty things barely visible to the naked eye to huge expanses of green 5 feet or more long and wide.  Leaves vary in shape and thickness too. But they are all one thing first, food factories. Their primary purpose is to absorb sunlight for the chemical reaction that produces food. Leaves may also protect plant reproductive parts, act as the plants liquid and gaseous waste removal system, and funnel water down to the plants roots.  And the leaves of some plants can also be reproductive parts, they can grow into new plants.  Many succulents can form a new plant if a leaf is stuck in the soil or even just lays on it.

Most leaves have a flat surface and are composed of two parts, the blade and the petiole -or stem. There are plants that have rounded leaves (conifer needles) and leaves that lack petioles.  When a leaf has no petiole it is called a sessile leaf.  (Important to know for plant identification.)  Monocot leaves, as in the grass families, may wrap around the stem at the leaf base, this is called the sheath. In cacti the leaves are modified into thorns and the stems are where photosynthesis takes place.

Pine needles are leaves

The blade of a leaf is composed of several layers.  Depending on the plant species the leaf may have more of one layer or type of specialized cells. The outer layer of cells is called the epidermis.  The upper epidermis tissue often has a thick waxy layer on the outside called the cuticle, which is protection for the tissue below. Small projections from the epidermis layer called hairs may also occur on leaves, usually on the upper side of the leaf but sometimes on the lower surface as well.  The hairs help protect the leaf from insects.  When a leaf has lots of hairs the waxy cuticle is less or absent.

Both sides of the leaf have epidermis tissue but on the underside of a leaf this layer may be thinner and not protected by a cuticle.  The stoma (“pores”) or openings for gas and water vapor to be released from the leaf are usually on the underside of the leaf.  Each stoma has two guard cells that regulate the passage of gas and water.  When the plant is lacking enough water the cells lose turgidity and the stoma are closed.  The stoma also close in the absence of light.

The layer of cells just under the epidermis is called the palisade parenchyma.  The cells in this tissue have stronger walls than other leaf tissue and this tissue forms the shape and support for the leaf.  Sandwiched between the layers of epidermis and palisade parenchyma is tissue called spongy parenchyma. The thickness of this layer determines the thickness of the leaf. The cells are loosely arranged within this layer and the veins of the leaf run through them. This is the layer that makes juicy lettuce leaves if its abundant or leathery leaves of rhododendron if there is less space and moisture between the cells.

Both types of parenchyma tissue have cells with lots of chloroplasts, which causes their green color and is where photosynthesis takes place.  They may also have chromoplasts that make a leaf appear gold, red or purple.  If chlorophyll, the green pigment in chloroplasts, is absent in places the leaf may have white variegation.  Because chlorophyll is needed for photosynthesis plants may not be as vigorous if large areas of the leaf are white. 

Types, shapes, and arrangement of leaves

Knowing how to describe leaves is very important when one is trying to identify a plant.  I suggest every gardener learn some basic terminology about leaf shape and arrangement because at some point you will be trying to identify a plant.  Plants of course did not evolve all of these leaf variations so we could recognize them, the variations may have practical use for the plant or they may just be random.

The first thing you need to know to properly describe a leaf is whether it’s a simple or compound leaf.  This is often the hardest part of identification for some people.  A simple leaf is one that has one blade attached to a stalk, the blade may be divided into lobes, but all lobes are connected at the base. Compound leaves have several small leaf parts, called leaflets attached to a center “stalk” called the rachis by tiny stems called petiolule.  The rachis attaches to the plant stem. Monocot leaves are usually simple leaves but dicot leaves can be either simple of compound. (For a definition of monocot and dicot see plant science lesson one.)

So how do you know if you have a simple leaf in your hand or a leaflet?  When a simple leaf petiole is attached to a stem it’s at a node.  There is often a tiny immature bud at the junction of leaf and stem petiole.  When the rachis of a compound leaf is attached to a stem you may see the same thing. But each leaflet attached to that rachis is not at a node and will not have that tiny bud.

Sumac has even pinnate compound leaves


Compound leaves are also divided into types.  When leaflets are arranged opposite each other along the stem with two leaflets at the end, the leaf is called even pinnate.  If the leaflets are opposite each other along the stem but there is a single leaflet at the end it’s called odd pinnate.  If the leaflets alternate along the stem and there are two leaflets at the end it’s called alternate pinnate.  Another type of compound leaf is called palmately compound.  The leaflets are joined in a circle pattern around the end of a rachis.  This is similar to the palm of your hand with your fingers sticking out.  Then there is the double compound leaf, which is what it sounds like one rachis of leaflets joins another rachis of leaflets and then both attach to the stem.  Whew!
 
This popular plant's leaves are palmately compound
 with serrate edges
Let’s now look at shapes of simple leaves.  (The shape descriptions can also be applied to leaflets.) An oblong leaf is just that.  An ovate leaf is egg shaped, wider at the bottom end. An obovate leaf is wider at the outer end.  An obcordate leaf is shaped like a heart with the point down.  A cordate lead is shaped like a heart with the tip up. A lanceolate leaf is narrow and pointed but wider than a linear leaf which is tiny and narrow. 

A peltate leaf is round, like a nasturtium leaf, a reniform leaf is half round, like a geranium leaf.  A hastate leaf is arrow shaped, point up.  There are other defined leaf shapes too, but these are the most common.  Some reference books will use simple language, like arrow shaped or egg shaped, which I bet you are glad to hear at this point.
An arum leaf has a hastate shape.

The edge of a leaf is also used to identify plants and leaf edges have many variations.  If the edge of a leaf is smooth its called “entire”.  A serrate leaf edge means it looks like a serrated knife blade, with sharp points.  Doubly serrate means larger “teeth” with smaller serrations between them. There are also incised, serrulate and dentate margins which are hard to describe but very similar to serrate edges.

This hosta has cordate leaves with entire edges.

If a leaf edge is wavy it’s called undulate.  If the edge is a series of rounded, small indentions its called crenate.  If the margin is sinuate the rounded points are larger.  If the leaf edge has large indentations in it’s outer margin it’s lobed. A maple leaf is lobed.  Lobes can be deep, almost splitting the leaf or shallow, like the lobes on many oaks. 

Oak leaves are lobed.

Are you shaking your head and looking confused yet?  Then let’s go on to leaf arrangement of simple leaves.  If they grow on both sides of a node across from each other they are opposite arranged.  If one leaf grows on one side of a node and then at the next node one leaf grows on the other side, it’s called an alternate arrangement. A whorl arrangement is when 3 or more leaves come from the same node.

Something to keep in mind as you try to identify leaf shapes, edges and even plants is that individual plants leaves can vary somewhat among the species. This is especially true of cultivars, where plants have been purposefully bred, often because the leaves are somewhat different from the species. New leaves may also look different from more mature ones.

Stems

The stem is the plant organ that supports the leaves and flowers and protects the vascular system that connects the roots to those organs. It can also be used for storage of starch and sugar. Stems expand and allow the plant to grow both upward and outward. Stems can be soft and flexible, or hard and unyielding, depending on what types of tissue they are made with and what their purpose is.  The trunk of a tree is a stem.

Along the stem are areas of meristematic tissue called nodes, where new growth of leaves, buds and smaller stems will arise.  The area between nodes is called the internode.  Nodes can be far apart or very close together, depending on the plant species and what growing conditions it has.



Stems are composed of epidermal tissues, cambium tissues, and ground tissue. Cambium tissues carry the veins of the plant. Ground tissue is called pith or wood in stems. Some stems can be hollow, with just a layer of epidermal tissue, a layer of cambium tissue under that and empty space in the center. Stems also have pores (stoma) to release gases and water vapor.  In plants with bark the openings in the bark are called lenticels.

Stems come in a lot of different variations. Some grow strongly upright, some are floppy or sprawl on the ground.  Some elongated stems climb up other things to the light and are called vines.  A very compacted stem with its nodes all close together is said to have a crown form.  Familiar plants that have crown type stems are strawberries, hosta, and dandelions.  Rhubarb and celery also have crown type stems.  You don’t eat the stems of rhubarb and celery, you are eating long leaf petioles.  All new growth on these plants comes from nodes on a compact stem close to the ground.  Cacti have thick, usually round stems that store a lot of water. 
 
Cabbage has a crown type of stem.
Tillers (runners) and stolens are stems that run along the surface of the ground.  Along the nodes of these modified stems new plants can develop.  Strawberries have tillers.  A stem that runs horizontally just under the soil surface is called a rhizome.  New plants also form at the nodes of this type of stem.  An iris has a rhizome stem.

Many people are amazed to find out that tubers, like the potato, are also underground stems.  The “eyes” of a potato are stem nodes. New plant parts can grow from them. Bulbs and corms are also modified stems.  The part of an onion that we eat is actually a stem, not a root.  A tulip bulb is a modified stem.  If you pull onions or tulip bulbs you can see the real roots growing out of the base of the bulb.  A corm, like the gladiolus corm, is a specialized stem.

Tendrils are modified stems.  As they grow toward the light they form a layer of woody tissue on one side and fleshy tissue on the other size, which causes coiling and allows them to grasp things to pull them toward the light.  Thorns and spines are modifications of the stems epidermal layer.

Tendril on gourd stem
  
Plants can be reproduced from stems, either as cuttings with nodes that can produce new plants or from nodes on tillers, stolens, tubers and rhizomes. Bulbs and corms produce tiny bulbils or cormlets along the base of the bulb or corm that can produce new plants.

Ok, I think I’ll stop here.  This has been a very quick overview of leaves and stems.  If you get deep into plant identification you’ll need to learn more terms describing plant parts.  But if you are interested in a subject you soon pick up the lingo.  Plants are fascinating so learn all you can about them.  Your homework is to look at the pictures of the paw-paw in the previous article and describe the leaf type and shape.

Spring Preview Cake

If a change in the weather is giving you spring fever but it’s too muddy to work outside stay inside and make this delightful cake.  You’ll need to pick up a pre-baked angel food cake or if you are really bored, bake one.

Ingredients
1 tablespoon unflavored gelatin powder (you can sub 2 tablespoons lemon Jello mix)
½ cup sugar
1/8 teaspoon salt
2 eggs, beaten
½ cup water
1- 6 oz can of frozen lemonade concentrate
2 cups of heavy whipping cream ( if you are really lazy substitute 4 cups of whipped topping)
1-10 inch angel food cake
Yellow food color optional

Directions

Mix together the gelatin, sugar, salt, eggs and water.
Cook and stir over low heat until the gelatin dissolves and the mixture begins to thicken.
Remove from the heat and stir in the lemonade concentrate. Add food coloring if desired.
Put this mixture in the refrigerator to chill.
Whip the cream until soft peaks form.
When the lemon aide mix is partially set, fold the whipped cream into it.
Tear the angel food cake into small pieces.
In the bottom of a 10 inch tube pan place a thin layer of the lemon aide mix.
Put about a 1/3 of the cake pieces on top, then pour 1/3 of the remaining lemon aide mix over them.
Repeat layers.
Chill the cake until firm, then unmold on a plate.

This cake looks great decorated with fresh or fake flowers. Don’t use real daffodils or narcissus flowers because they are poisonous.

Do February showers bring March flowers?

Kim Willis
 “He who has a garden and a library wants for nothing” ― Cicero

© Kim Willis - no parts of this newsletter may be used without permission.

And So On….

Find Michigan garden events/classes here:
(This is the Lapeer County Gardeners facebook page)
An interesting Plant Id page you can join on Facebook

Here’s a seed/plant sharing group you can join on Facebook

Newsletter/blog information

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I write this because I love to share with other gardeners some of the things I come across in my research each week. It keeps me engaged with people and horticulture. It’s a hobby, basically. I hope you enjoy it. If you are on my mailing list and at any time you don’t wish to receive these emails just let me know. If you know anyone who would like to receive a notification by email when a new blog is published have them send their email address to me.  KimWillis151@gmail.com



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