Larry, I gave them 10-10-10 early early in the spring, and a second application later, plus we have quite a bit of rain. Same fertilizer process as usual, except for all the rain. These seedlings putting up double scapes are three and four years old. I can't believe how much the seedlings and registered plants have grown in a week's time with the hot temps and rain.
During the winter, hubby collected rain water to use on the seedlings
inside the house. They grew so well, I had to trim many times to make them easier to work with. A few I didn't trim grew to 3 feet tall before trimming. No fertilize for these seedlings. They didn't need any. We had a bountiful supply of rain water, so the plants did not get our tap water which the plants do not like. Plus once the new seedlings were planted outside, they are getting plenty of rain. These have been fertilized once with 10-10-10. They are growing great so far. I'll give them another fertilizer application in a few weeks.
It would be so great if just the right amount of rain continued, but during the
hottest months of summer, we usually have a period of drought.