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Last week the Pennsylvanian and Iowan branches of the family converged in Quantico, Virginia to celebrate our nephew’s graduation from the Marine Corps Officer BASIC school. We had a beautiful day to fête this accomplished young man of whom we are all so proud. I, of course, couldn’t help also staring at the flowers.

Quantico is firmly in USDA Zone 7. The daffodils were all in full bloom, not just the ones on the south-facing slopes like at home. The flowering pears were spectacular, the star and saucer magnolias were in their glory and the Yoshino cherries that the DC area is so famous for, almost caused me to get in a car accident. After that my husband figured he better drive.

Here in Lancaster County we are in Zone 6, meaning the coldest temperatures we experience are -10F. Those days are thankfully few and far between, but they do happen. Zone 7 buys you about 10 degrees, staying above the 0F boundary. Folks in Zone 7 are usually about two weeks ahead on the gardening calendar as well. Hence their breath-taking trees. My family in Iowa is in Zone 4, otherwise known as the Frozen Tundra. There they routinely experience winters where the mercury dips to -20F or even negative 30F. That kind of cold just makes me angry. They cannot grow many of the plants we so cherish in spring, ornamental cherries and dogwoods, many hydrangeas and other flowering shrubs that are not bud hardy under those temperatures. Something they can grow well is hostas. Hostas are so successful in my in-law’s yard that they have been seen sprouting from the compost pile when divisions were pitched. Gotta love hostas.

My sister-in-law is driving with our new 2nd Lieutenant down to Pensacola, Florida for flight school. The panhandle of Florida is smack in the middle of Zone 9. Rarely does it even freeze there. She may never go back to Iowa.

But I digress. The purpose of this article was supposed to be about how spring is coming, but it isn’t truly here yet. Every year we see intrepid gardeners who buy their tomatoes the first week of April under heavy caution not to plant them for at least four weeks.

But what can one do in the yard this time of year? Now is a great time for clean-up. Clear away the leaves and debris from last fall and see what is beginning to emerge. Cut down your ornamental grasses and pull out any residual annuals.

If you are gung-ho to start planting, shrubs and perennials overwintered with minimal heat or mail-order bare root should be fine as well as cold-hardy annuals like pansies and calendulas. Early vegetables, artichokes, lettuce, broccoli, cabbage and the like also can go in now- but keep covers handy in case a frost is predicted. A light frost won’t kill hardened off plants, but will often discolor the leaves.

For most annuals and summer vegetables like tomatoes and peppers just wait. The plants will be better cared for at the greenhouse than in your garage.

Spring is springing in Virginia, and it is on its way north, but patience, as my father often reminds me, is a virtue.

If you are like me, you’ve probably gotten numerous seed catalogues (and emails from seed companies) since January. Maybe you’ve daydreamed of warmer days and ordered some new flower or vegetable seeds to add to your garden this year.

Most annuals and vegetables grow best when it is warm. If you wait until the soil is warm enough to germinate petunias or peppers, it will be fall before you can enjoy your garden. Starting seeds indoors will give you a jump on the season so your baby plants are ready to go out as soon as the soil and weather are appropriate. Keep reading for some tips and tricks to successfully start seeds at home.

Know your frost-free date. Here in Southern Lancaster County, we have had our last frost as early as April 28th and as late as May 20th. I usually caution people to look at the weather report the last week of April. If the 10-day looks good; you’re probably in the clear. Seed packets list how long the seeds take to sprout and be ready for transplanting. Use that estimate to count backwards. No sense starting tomatoes in January- they’ll be trees by May 1st.

Use sterile potting soil designed for seed germination. Lots of companies manufacture sterile potting soil that is a mix of peat, pearlite, vermiculite and a few other minor components. It is light, wets well, drains well, is free of contaminates and is best for starting seeds.

Use clean containers. You may have old packs left from last year, or purchased special seed starting trays. You may prefer biodegradable pots or special expanding peat pellets. Whatever you use, make sure it has drainage holes and is clean.

Seeds need warmth. In the greenhouse I have a water heater which pumps water through tiny tubes on the benches to provide bottom heat of about 65-70 degrees. This is not feasible at home. You can buy electric heating mats to start your trays on, but as long as you have a warm spot, that’s not necessary.

Seeds need moisture to germinate. Keep the soil damp but not sopping. Cover with plastic wrap or special tray covers to keep humidity high at the soil surface. Germination is a fascinating process comprised of several steps. First, the tough seed coat that protects the tiny embryo inside the seed swells with water and cracks open. Next,  the embryo wakes up and starts to metabolize the starches and proteins in the endosperm and/or cotyledons. The baby root (radicle) emerges and starts burrowing into the soil. In the final step, the stem (hypocotyl) and seed leaves (cotyledons) emerge. Without moisture,  this process stalls.

Seedlings need light. While most seeds don’t need light to germinate, they do once they’ve sprouted. As soon as the seedlings have leaves they start photosynthesis. Seedlings grown without enough light are spindly and weak. If you have a very sunny window and only a few plants, that will probably work. Otherwise, you better get some lights. Grow lights have incandescent, fluorescent or LED options. The wavelength needed for growth is a balanced white light, though supplementing with blue or green may beneficial. Light more towards the red spectrum is best for flowering (not seedling growth). A full discussion on grow lights is beyond the scope of this article. But feel free to nerd out on the internet.

Seedlings need fertilizer. Once the seedling have their first set of true leaves, (several weeks after germination) begin lightly fertilizing. Think about half-strength of what you would use for hanging baskets or patio containers. We use about 100ppm of nitrogen twice a week. If the seedling look yellowed, fertilize more frequently. Once your plants have two-sets of true leaves, you can transplant your seedlings to larger pots or packs and begin to harden them off.

Don’t skip hardening them off. In greenhouses we lower the temperatures 5-10 degrees every week or two after transplanting. We have large fans and shutters that force air through the houses to cool and provide air circulation. As soon as possible, we move the spring vegetables, pansies and other cold tolerant annuals outside. You can’t take a young plant that was growing inside at 70 degrees with no wind and no direct sunlight and put it outside and not expect some shock. Do it gradually. If you have a cold frame, great. Open the covering during the day, close it at night. If not, put young plants on the porch or in a partly shaded location for a few hours each day for at least a week before you are ready to plant into the ground. Exposure to wind, changing temperatures and higher light levels causes hormonal changes in the plants that toughens the stem. This process helps plants resist breakage and other environmental stressors. One clever gardener I know puts her transplants on a wagon and simply wheels it out to her driveway when she leaves for work, and back into the garage when she gets back home again.

Spring is coming, the days are getting warmer, and greenhouses around Lancaster County are filling up with young plants. Summer will be here before we know it. 

Last week’s article mentioned the hormone auxin and how it affects plant growth. I got a lot of feedback asking about other plant hormones. So prepare yourself for a science lesson.

Hormones work like a lock and key mechanism. The plant either produces the hormone or it is applied to the crop and the hormone molecule “key” fits into receptors “lock” to turn on an action in the plant. Just like putting your key in the ignition of your car turns it on. Hormones can be blocked by using chemicals to fill the spot in the receptors without turning the action on. You will see how farmers and plant scientists use this to their advantage below.

Ethylene is the best well-know hormone among non-plant scientists. It is the only hormone that is a gas. It is primarily responsible for fruit and seed ripening, and flower maturity. Ethylene ripens your bananas and tomatoes and why your cut flowers only last a few days. It is also involved in strengthening the stems when plants are brushed by animals or blown by the wind. In addition, it plays a minor role fighting disease and insect damage.

Plant and food scientists use ethylene to ripen fruit that is picked green to ship without bruising. Greenhouses use ethylene to prevent young plants from flowering too early. Florists use ethylene blockers to prolong the shelf life of cut flowers and poinsettias.

Gibberellins are plant hormones that promote stem elongation and plant growth. They control the distance between each set of leaves (nodes) on a stem. The internode length is very important to farmers. Greenhouses spray plants that have a tendency to get too leggy with gibberellin blockers to make more compact growth. Cut flower producers and sugar cane growers that want long stems apply gibberellins to their crops.

Cytokinins have the very important job of controlling cell division. It is produced in the root tips and travels up the plant with the water in the xylem. It works in concert with auxin to control whether cells will become leaves, stems or roots. It is also involved in wound healing and sealing cuts to the stem. Plant scientists use this hormone when growing plants in tissue culture. Tissue culture propagation is used to make many plants out of a small piece of a leaf. Coral bells, hostas, and other high dollar value perennials are started this way. The ratio of auxin and cytokinin in the tissue culture medium determines whether shoots or roots grow.

Abscisic acid is the plants way of dealing with water stress. When a plant is experiencing drought, it emits absisic acid to close the pores on the leaves to prevent water vapor from leaving. During extreme drought, abscisic acid causes flowers and fruit to drop so the plant doesn’t have to waste energy on those structures. Plant breeders select plants that are extra sensitive abscisic acid as they are more drought resistant.

There are several other minor hormones like jasmonic acid that are involved in plant defense. When an insect nibbles, or a fungus attacks, jasmonic acid turns on the defense system. We are also learning how trees can communicate with each other through the roots systems. When one tree is attacked, jasmonic acid is emitted by the roots to be sensed by other trees in the area to turn on their defenses as well.

Plants are complex organisms, yet don’t have a way to get up and leave when they are challenged by their environment. Hope you enjoyed this discussion of how hormones help them out and how farmers and scientists use them to make the best plants for you.

Mike McGrath, the host of a popular radio gardening show has this to say about fall pruning "The rules of fall pruning are simple: Prune nothing in the fall! That’s nada! Bupkiss! Zilch! Zero!" I 99% agree with him.

Plant growth, like animal growth, is governed in part by hormones.

The hormone auxin is produced in the growing tip (meristem). It has two main jobs- the first one is to promote root growth. That's why most rooting powder contains IBA, a synthetic auxin.

The second job is to stop the lateral branches from expanding. Why? To preserve apical dominance- this is very important in trees to maintain a strong central leader. When you pinch an annual or perennial or prune a shrub you remove that source of auxin, changing the hormone balance of the plant. Suddenly the side branches can grow out. That is great for creating fuller, or bushier plants. The problem comes when you prune shrubs in the fall. Promoting a lot of new growth as the plant is trying to enter dormancy is counter productive. Often these side shoots don't have time to harden off before frosts and are damaged.

Another reason to not prune shrubs in the fall is many of our spring-flowering shrubs like forsythia, lilac, mock orange and viburnums set their flower buds in the late summer for the following season. Pruning those now cuts off next spring's flowers. Those are best pruned right after flowering if necessary.

Most summer flowering shrubs like butterfly bushes and crape myrtles bloom on new wood so pruning them in the fall won't affect new years flowers. BUT they tend to be less hardy and often suffer cracks in the crown when ice forms in those fall pruning cuts. These are best cut back in late March or early April as they are starting to wake up from winter.

If your shrub has dead spots, broken limbs or crossing branches, this is an exception to the rule. Remove diseased or dead limbs as soon as possible to prevent the spread of infection. However- be sure to disinfect your clippers with rubbing alcohol between cuts.

So sharpen and oil your pruning shears...and then put them away until next year.

We are coming to the end of the 2018 gardening season. Never will I be so happy to see the end of a year.

The Greek poets noted everything is best in moderation. We certainly had more than moderate rain this summer! There were some definite winners and losers from the extra moisture.

All the extra rainfall was hard on the vegetable garden. We did get some good tomatoes between the raindrops. But yields were low. I heard some reports of tasty melons, but ours didn’t pollinate well, and so we got very few. Broccoli and cauliflower is now struggling to make heads before it rots. Pumpkins didn’t pollinate well, and ones that did have mostly collapsed. Greenbeans did well, especially the late planting, we are still getting a good amount.

The good news is we didn’t have to drag the water hose around much and all my summer-planted shrubs are thriving. We planted some weigela, crape myrtles and hydrangeas around the house as well as some new perennials along the hill in front of the sales areas. Planting shrubs in July can be hit of miss as it is import to water them in well to prevent transplant stress and to help them get established. That was an easy job this summer.

Weed control this year is crucial. The rain encouraged seeds in the seed bank germinate quickly and they are growing rapidly. Now is a great time to work on the weeds. Prevent annual weeds like ragweed, black medic, smarteed, crabgrass and pigweed from going to seed by mowing, pulling or weed whacking. They are generally shallow rooted and can be pulled easily especially because the rain has softened the soil. Even if you don’t pull them, the frost will kill the tops and the roots are not winter hardy. The key is preventing them from going to seed.

Perennial weeds are a bit more of a challenge but use their physiology to your advantage. Perennials are now busy transporting storage carbohydrates to their root system to prepare for next spring before they enter winter dormancy. Perennial weeds like bindweed, knotweed, poison ivy and thistle often have deep taproots and are difficult to pull. Even if you get most of the root, small pieces left in the soil can regenerate. They are best treated with an herbicide because the plant will transport the chemical down from its leaves and stems to the crown and root along with the storage starches. Use targeted herbicides based on what weeds you have. Don’t leave herbicide treatment til the spring as then the juices are flowing the opposite direction and herbicide can easily be outgrown.

Fall cleanup has become a topic as dangerous as discussing Social Security. There is the avid “Leave everything alone until spring” camp and those whose lawns are so free of leaves and standing perennials they must spend every free moment raking. I fall somewhere in the middle. I like to mow the leaves that fall and mulch them into the grass. The huge sycamore leaves that fall in the flower beds, I try to clean up and usually burn, then rake the ashes back into the beds as potassium. They don’t break down well otherwise. I leave some of my coneflowers and other daisy-type perennials to feed the goldfinches but cut the ones in some of my fuller flower beds down so they don’t reseed like crazy. I always leave the ornamental grasses standing and summer flowering bushes like butterfly bushes, crape myrtle and caryopteris alone. Pruning them in early April is best. It helps prevent ice from forming in the crown which can be a death blow to tender shrubs.

Many of our beneficial insects and butterflies overwinter in leaf litter, so leaving several areas alone as habitat is a friendly thing to do for those bugs that really will help out combat aphids etc next summer.

It is a good idea to remove any plants or leaves that are diseased. My hydrangeas got pretty bad leaf spot this year mainly due to the weather. I’ll be raking and bagging them for disposal as soon as they drop. I’ll also cut back some of the mildewed Black eyed susans and tomatoes as I don’t want those spores overwintering in the ground to reinfect my plants next season.

I see the sun this morning as I write this. Sunny days have been few and far between this summer. I’ll do my best to enjoy this day, and pull a few weeds too.

Pictured above: Panicum virgatum 'Northwind'