Can You Plant in Summer?

July 19th, 2016

One question I get fairly often this time of year – a point when people tend to notice that their yard is, ah, “lacking” – is whether it’s possible to plant in summer.

Both container-grown and balled-and-burlapped trees can be planted in summer.

The short answer is that although it’s not the ideal time, yes, you can plant most plants in summer.

The key, as I’ll get to in a minute, is vigilant watering.

The two prime planting windows in central Pennsylvania are between the end of winter and the end of May and then again right after Labor Day through October. That’s because temperatures are typically cooler then, rain happens more often, and the sun’s rays aren’t as direct.

All of that helps mitigate the shock that young plants experience when they’re suddenly moved from the cozy pots and coddling of nursery life to the harsher conditions of your lousy soil, erratic weather, and bug, disease and rodent vulnerability.

That doesn’t mean that summer planting is a bad idea, though. It just means you’re going to have to pay more attention to overcome the challenges that spring weather helps overcome better than summer weather.

Consistently damp soil makes the difference between plant life and death – especially during the first 6 to 8 weeks when those shocked plants are trying to re-root and acclimate to the new conditions.

Summer-planted small-rooted plants such as annual and perennial flowers benefit from soakings every 2 or 3 days – even once or twice a day in the case of new grass.

Summer-planted bigger plants such as trees, shrubs and evergreens benefit from deeper soakings every 5 to 7 days as opposed to shallower daily-or-so watering.

Keep those new summer-planted plants consistently damp.

Remember, the idea is to keep the soil consistently damp all around and to just under the rootballs of transplants. Bigger plants need more water but less often, while smaller plants need less total water but more frequently since the soil surfaces dries first.

Transplants might wilt soon after summer planting, but if they’re watered right away and kept damp, they should bounce back quickly. The appearance of new little leaves is a good sign.

You’ll lessen wilting and increase your odds of success by planting in the evening or on a cloudy day – especially before a rain.

Plants will acclimate much better if they don’t have to go through a full day of hot, direct sun right off the bat. Evening or cloudy-time planting gives them a half-day or more to adjust to transplant shock under dimmer, less harsh light.

Also helpful is planting during a cooler period in summer. Plants are more likely to wilt and/or shock if you plant when daytime highs are in the 90s vs. when they’re in the 70s.

After the initial planting, summer-planted plants shouldn’t wilt. If they do, the answer isn’t fertilizer. It’s water ASAP.

Keep in mind that too much water is also bad, although far less likely in the heat of summer. Ironically, the symptom of excess water is the same as not enough water: wilting.

The reason for that is that soggy soil can kill roots, and lack of roots means a plant has lost its means of drawing water from the soil into the leaves and stems. Without that moisture, the top growth wilts.

A good way to determine if your soil is damp enough is to simply stick your finger into the ground next to the plants. If it’s already wet, no need to water. If not, get out the hose.

The exception to summer planting is plants sold “bare root” – i.e. dug and washed of soil. It’s how many mail-order plants are sold so as to avoid the cost of shipping heavy soil.

Bare-root plants are generally sold only when still leafless and dormant toward the end of winter.

You might also run into “balled-and-burlapped” trees and shrubs at the garden center and nursery. These are plants that have been grown in a field, then dug up with soil attached and wrapped in burlap for transport.

So-called “B&B” plants have soil protecting their roots and aren’t bare-root, which makes them OK to plant in summer.

By far, most plants these days are container-grown. These are plants that have been started in pots in a nursery and sold that way until you un-pot them for home planting.

Container-grown plants transplant well any time the ground isn’t frozen. In fact, you could argue that they’d prefer to be in the ground in your yard instead of stuck in pots all summer on a garden-center surface.

That’s assuming you’re going to keep them watered…