The hot and humid days of summer are certainly not ideal for planting, but you can plant in summer with some special care and vigilance.
Maybe you just found a fantastic plant you have been looking for, or, perhaps you didn’t get around to planting some native perennials or shrubs you bought in the spring. Keeping plants in containers over the summer requires constant watering, so what should you do?
Best Times for Planting
The best practice is to plant when the days are warm and the nights are cool. These conditions encourage the best root development and cause the least stress to plants. When are these ideal times? In much of the country, it’s mid to late spring, very early summer, and early fall. For hotter climates like the Southeast, the West and Southwest, you might be best off planting in the winter. Make sure to plant at least six weeks before hard frost, where those conditions occur.
So, should you plant now in the middle of summer? For hotter climates, it’s not a great idea. For areas with four distinct seasons, try to wait until early fall. Vacations have killed many a newly-planted plant – if you are going away and you don’t have someone to water, just don’t plant in the summer.
Tips for Planting in the Heat of Summer
If you decide that you simply must plant in the dog days of summer, here are 15 tips to increase your chances of success:
- Plant in the evening – especially in areas that get full sun.
- Plant on a cloudy day when there is little chance of sunshine.
- Plant just before a rainstorm is coming.
- Water plants in extremely well immediately after planting.
- Ensure that any new plants get a good drenching 2 or 3 times a week from you or Mother Nature (don’t over-water plants that like drier soil)
- Water early in the day to allow foliage to dry off to help prevent fungal diseases.
- Water the roots, not the foliage, either by hand, with a soaker hose or drip irrigation.
- Select larger plant material. Larger pots of plants will often have a higher survival rate than plugs or small pots, especially in hot weather.
- Avoid buying overly-fertilized plants that are loaded with salts – they are highly susceptible to drought.
- Buy plants that are potted in real soil, not a soil-less mix – these will be much more drought-tolerant.
- Choose regional native plants that are organically grown – they will be better adapted to your landscape conditions.
- Don’t add traditional fertilizer when planting, which is often loaded with drying salts. Instead, toss a handful of compost in the planting hole to increase water retention (except for plants that don’t like fertile soil, such as most native grasses)
- For trees and shrubs, add a soil amendment to help water and nutrient uptake. I like Stress-X from North Country Organics).
- Mulch around newly planted plants with a 50/50 mix of an organic mulch (like shredded bark mulch) and organic compost. This helps to increase water retention around the plants
- Monitor, monitor, monitor. Plant mortality can occur much more quickly on oppressively hot days.
Native Plants & Establishment
Remember that native plants are low-maintenance, not no-maintenance. With regularity, casual gardeners install native plants with the misconception that native plants can simply take care of themselves after planting. All plants must be irrigated by you or Mother Nature, until they have established. The first growing season is critical for proper irrigation, and depending on the weather conditions, the second growing season can be quite important as well.
Buying plants that have been locally sourced and locally grown in your region will also help with proper adaptation in your landscape. Buying a tree that has been grown in clay soil in the Southeast, and planting it in sandy soil in the Northeast will likely ensure a short lifespan. Follow a locavore’s approach when buying plants.
Right Plant, Right Place? Usually, But…
Planting the right plant in the right place will go a long way toward successful establishment. Every plant enthusiast has broken this rule at some point. Sometimes you get lucky with plants that tolerate a range of conditions, but most times, the results won’t be good.
There are exceptions to every rule, though. Dan Jaffe, Propagator at the New England Wildflower Society, shared some interesting information about Actaea racemosa (Black Cohosh) – a plant that is usually found in moist shade conditions. Dan spread Black Cohosh seed under hemlock trees – a dry shade condition which few plants can tolerate. The seed that germinated was surprisingly drought tolerant. Live plants installed in that same condition would not survive. This example makes a great case for sourcing and propagating local native seed.
Best Case – Wait Until Fall
The best case may be to skip the stress of summer planting and wait until fall. And when I say stress, I don’t just mean plant stress – it’s stressful on us gardeners, too! Even if you planted in the gentle days of spring, summer droughts can wreak havoc on newly planted plants. Monitor new plants closely and water as needed. This is especially important for native plant plugs that have not yet developed a strong root system.
Have a happy summer in the garden from Kim Eierman at EcoBeneficial!