A few weeks ago, I bought some hydrangeas on sale to fill the space left by my many hostas donated to the Feed-A-Deer program. I got two in the ground straight away and they seem t be doing well. However, Craziness occurred as is usual in my life and I did not get them in to the ground. the other two are still in the pots and today I suddenly have time to put them into the ground. However, today is supposed to be hotter than hell's back door (upper 90's) and will go on for weeks. (July in DC area.) The spot where they were to go gets a lot of morning sun and I fear for these guys ability to cope. Should I wait? Should I stick them into the ground with a song and a prayer? Or should we move away from this god forsaken place? Internet sources tell me to plant spring and fall which is why they were on sale, I suppose. I have kept them watered and with short exposure to morning sun (approx 1.5 to 2.0 hours). They are quite beautiful! One is a Firelight and the other a Merit Supreme. Can you advise? Cheers, Leland Bryant, MFA-IA
You're correct that this isn't the ideal time to plant new shrubs, but it would be better to plant them in the ground rather than leaving them in their pots. Give them a good watering before you take them out of the pots. Take care to dig the planting hole correctly and tease out the roots from the root ball to help them get established in the native soil (especially important if you see roots encircling the inside of the pot -- referred to as being "root bound").
You will have to make sure to keep the plants well-watered now, as the high temperatures are going to be stressful until the roots "take" to the soil. Watering deeply once or twice each week is better than frequent shallow waterings.
Refer to the following pages for information on the planting process and after-planting care: