August has a reputation it does not deserve. Plenty of gardeners write the month off, assuming the planting season is essentially over once the calendar flips past July or even June. The truth is closer to the opposite. August is one of the best windows of the year to get trees, shrubs, and perennials in the ground, if you understand what makes the timing work.
Why trees and shrubs do well planted in August
Soil temperature is the key factor most people overlook. By August, the ground has been warming all summer and holds onto that heat well into fall, even after air temperatures start to cool. Warm soil keeps roots actively growing, and root development, not top growth, is what determines how well a newly planted tree or shrub survives its first winter. A tree planted now has roughly two and a half months of strong root-building weather before the ground starts to cool in earnest, which gives it a real head start over something planted next spring.
Coreopsis Uptick™ Yellow and Red
Perennials that establish well in late summer
Perennials behave the same way. Plants like Coreopsis Uptick Yellow & Red, with its long bloom time and dark red centered flowers, and Achillea ‘Firefly Sunshine’ yarrow settle in quickly when soil is warm, and most will have a full root system in place before frost. The bonus is that many late summer and fall blooming perennials are putting on their best show right now, so you can see exactly what you are getting before it goes in the ground.
Achillea ‘Firefly Sunshine’
What August planting requires from you
The one non-negotiable with August planting is water. Spring planting often gets help from regular rainfall, but August can be dry, so anything new in the ground needs a consistent watering schedule or even soaker hoses for the first several weeks regardless of what it is. Deep, infrequent watering trains roots to grow downward and is far more effective than a quick daily sprinkle.
Stop by Hornbaker Gardens this month to see what is in peak form right now and to talk through what would work best in your space.