How to avoid transplant shock
Although April is one of the year’s best months to plant trees, shrubs, evergreens and perennial flowers, it’s still stressful for plants to be evicted from their cozy pots and coddled nursery care into the real world of lousy clay, erratic weather, and the all-too-common planting miscues of inexperienced gardeners.
Plants often let you know when they’re not happy by what’s known in the industry as “transplant shock.”
This can show up as wilting, brown leaf/needle tips, dieback, and in the worst case, plant death.
Some ways to ease the transition:
1.) Protect the plants from wind on the way home from the garden center or nursery. If you toss evergreens and leafed-out trees and shrubs in the back of a pickup, you’ll expose the foliage to near-hurricane-force winds on the drive down the highway.
This can create moisture deficits and wind-burned plants even before you get them in the ground.
Either store plants inside your vehicle or cover them with burlap, a sheet, or a tarp for the ride home.
2.) Pick a cloudy spell to plant. This lets you transplant without the plant being immediately hit by full sun.
Cloudy days draw less moisture from plants than sunny days and make the transition into the ground a bit less taxing.
If you plant on a cloudy day right before a soaking rain, so much the better. The roots will get a comforting bath right off the bat.
If you can’t avoid sunny-day transplants, wait until evening to plant. The transplants will get a nighttime break first thing before having to face bright sun.
3.) Free the roots while doing as little root damage as possible. Yes, you should loosen bound and circling pot-grown plant roots to encourage those roots to grow out into their dirty new home.
However, don’t just rip them apart. Try to tease the roots apart or use your fingers and a hose or water-filled basin to free the roots without injuring them.
4.) Water after planting. Soak the soil around your transplanted plants immediately after planting to settle air pockets and make sure the roots are in contact with damp soil.
Make sure you’ve watered enough to wet the whole way around the rootball and down to just below the bottom of the rootball.
Don’t skip watering because it’s supposed to rain. Forecasts aren’t always right, and rains don’t always dampen as deeply as you think.
Keep the soil consistently damp the entire first growing season by watering whenever rain doesn’t do the deed for you.
- Read George’s tips on how often and how much to water new plants
5.) Be ready with a burlap shield or similar shading device. Especially if you’re planting in a sunnier, less-protected spot than the plant was displayed at the garden center or nursery, plants might be overly sensitive to sun and wind at first.
If you see leaves “bleaching” white or scorching around the edges, help them gradually adapt by erecting a barrier of burlap or dense netting to give some shade and wind protection.
Ready the wildflower seeds
If you’re planning to start a wildflower meadow or garden from seed this year and don’t have the seed yet, get it ASAP.
Orders are taking longer than usual this year, so give yourself some lead time since May is the year’s best month to plant wildflower seed.
- Read George’s post on how to start a mini-meadow from seed
A good wildflower seed blend should have between 15 and 25 different species, according to Mike Lizotte, author of the book “Mini Meadows” (Storey Publishing, 2019, $16.95 paperback) and owner of the Vermont-based American Meadows seed company.
Most wildflower mixes also include both annual flowers and perennial ones.
Annuals are the ones that will bloom the first year, then die and drop seed (at least in some cases) to flower again in future years. Examples are cosmos, marigolds, and zinnias.
Perennials typically don’t bloom the first year but should flower the second year and beyond as they establish and begin to spread. Examples of those are coneflowers, black-eyed susans, and goldenrod.
Although consistent watering is important in getting the new seeds to sprout, covering them to protect against bird-feeding isn’t.
“You could apply a light covering of straw over your seeds once you’ve planted, but just make sure you keep it light as you still want moisture, sunlight, and your seedlings to be able to penetrate,” American Meadows says in its “Growing Your Own Wildflower Garden” fact sheet. “Unfortunately, some people cover (seeds) too densely, smothering them and hampering germination. In most cases, it’s not recommended to cover. Let the birds or other wildlife have a snack… It won’t have an impact on the outcome of your meadow.”
Be ready for weeds to come up along with your purchased wildflower seeds. Weed seeds are in all soil, and when you disturb soil and start watering, they’ll germinate, too.
How to tell the difference between weeds and the “real” flowers before you start yanking?
“Look around the area and see if the suspicious plant is evenly distributed over the meadow area,” American Meadows advises. “If it is, it’s probably one of your wildflowers. If it’s just here and there or in a clump or two, it’s probably an intruder from weed seed that was in your soil when you planted.”
Later in the season when it’s more apparent which are the weeds and which are the flowers, yank the weeds as soon as you’re sure – or at least cut off any weed seedheads so they don’t mature, drop, and contribute to future weed problems.
Besides American Meadows, another good source for wildflower seed is the Meadville-based Ernst Conservation Seeds.
Fend off allium leafminers
If you’ve had trouble the past year or two with your once-easy-to-grow onions and leeks rotting, the problem could be the allium leafminer, sometimes called the onion leafminer.
This bug is a fairly new one that first showed up in the U.S. in Lancaster County in 2015.
Since then, it’s been spreading throughout central and southeastern Pennsylvania as well as into Maryland, New Jersey, New York, and Massachusetts, according to the Pennsylvania Department of Agriculture.
The adult flies emerge from the soil this time of year and start mating and feeding on the sap from onion, leek, chive, and garlic leaves.
A telltale sign of impending trouble is a line of light-colored dots on the leaves. Those are caused by females making holes to lay eggs.
The creamy-yellow, maggot-like larvae hatch from the eggs and tunnel down the leaves, where they and the pupal stage bore into the bulbs. That stunts the plant’s growth, opens the plant to disease, and often rots the bulbs altogether.
Berks County’s Rodale Institute did a recent study that found an effective control is simply covering your onion-family plants with a floating row cover.
Row covers, which are available in most garden centers and garden catalogs, are light enough to let in sun and rain but dense enough to keep leafminer adults from laying eggs.
- See George’s video on floating row cover
The key is getting the row covers on before the adults emerge. Rodale says that adults, on average, emerge in our region around April 20.
To determine if and when adult leafminers are present, the state Department of Agriculture suggests setting out yellow sticky cards or yellow plastic bowls of soapy water.
The flies are attracted by the color yellow. Coating a yellow card or board with TangleTrap or petroleum jelly acts like a fly trap, which not only helps you identify the pest but prevents captured ones from laying eggs.
Leafminer adults look like small houseflies with a yellow-orange head.
Rodale advises keeping the row covers in place at least until the first or second week of May, when adults are typically done laying eggs.
Otherwise, several insecticides are available to control allium leafminers, including the organic options azadirachtin and Spinosad.
- See Penn State Extension’s list of insecticides labeled for allium leafminer control
If you’re growing a later crop of onions or if you let leeks stand into fall, a second generation can lay eggs in those crops in September. Pupae then overwinter in the soil.
- Read Penn State’s fact sheet for more on allium leafminers
- More when-to-do-what tips: George’s “Pennsylvania Month-by-Month Gardening” book