I bought a cornus florida rubra from a discount store for 14 dollars.It looked prety good there but now looks dead. I have been watering it a few times a day here in Ohio due to 90 degree heat. Now I'mreading they can be overwatered. I dug the hole pretty wide and roughed up the sides of the planting hole so the roots could develop.There was a previous big king crimson maple on the site,and I found some of those roots still in there.Now I'm wondering if it was a poor location.The maple was cut down about 5 years ago,and the dogwood was just planted in May.I s it just settling in or is it totally gone?( Due to overwatering or root competition.)
I'm no authority, but watering a few times a day is much more than excessive. Especially since they need good drainage, which means not standing in water. They die quickly if they stand in water. I have two new Cornus florida planted in full sun, 85-88 daytime, with lots and lots of wind (30 mph today, but many day to 40+ mph), and I have been watering at most 2 times a week. There has been good 1 inch rainfalls most weeks, and so I've only watered 1x most weeks only when the soil is feeling dry to the first knuckle.
rosi, if you end up replanting with another dogwood, the best time to plant them is as early in spring as possible. For many trees a fall planting is best, but the research for dogwoods says to plant in spring, assuming the ground is not frozen etc. If you buy a container tree or a balled and burlaped tree, try to get them as soon as they arrive. This gives the new tree the most time possible to acclimate, and develop roots before the really warm months arrive.