I just planted some coreopsis and I would like to know how often to water them. The temp. is supposed to be in the high 80's - low 90's the rest of the week.
For the first 5 days, provide shade from afternoon sun. This can be done by inserting stakes/sticks into the ground and covering with a paper or leaf bag. The roots need time to settle in before they can cope with severe heat. These are drought tolerant plants but any perennial needs regular moisture its first summer. That may be every 3 days for the first week or two and then weekly afterward.