OK I am trying to get the conditions just right for my Calla lilies so they will thrive next summer, so I need some input.
I have Callas in 2 different locations, both have the same type of soil. In location #1,I planted these callas at the end of April and they began growing mid-May. 1st blooms appeared around June 7th. These callas had some morning sun, then were in full sun from 11:30 to 2:30, and full shade after that. They bloomed in big, bright colors beginning in June and most stalks/flowers rose an inch or two above the foliage. However, by July 15th only 2 of the 6 were still flowering nicely. Then by the end of July began to go dormant. After July there were no more flowers but some Callas produced foliage for 2-3 weeks more. Yet the foliage only grew anywhere from 2 inches to about 8 inches.
In location #2, I planted these Callas about June 1st and they started growing mid-June. First blooms appeared around July 10th. These Callas were in full shade until about 10:30. Then from 10:30 to about 3:00pm received full sun, and were shaded the rest of the day, with the exception of maybe 1/2 hour of filtered evening rays coming through a tree around 5:30pm to 6:00pm. The flowers were not as vivid in color, some seemed almost faded. Some even seemed like a white bloom, while the main color (purple) appeared as the secondary color. The flower stalks were much shorter than those in location #1 and rarely were higher than the foliage. Some of these started blooming mid-July, but after the 3rd week of August produced no more flowers. The foliage in this location was beautiful, lush, and tall, and is just now started to wind down.
Both sections received a good amount of water, but I must admit, Section 2 probably received more and a deeper watering because the hose reached it. I had to hand water section #1. I fertilized each with a slow release fertilizer when I planted them.
I want all my Callas to be productive, lush and thrive, so I have some questions.
1) Should I move all of them to another location which only receives morning and late afternoon sun?
2) Should they not be planted in a location that receives sun during the hottest part of the day?
3) Do they grow and flower good in mostly shady areas?
4) What is the best fertilizer for Calla Lilies?
5) When should I start fertilizing and how often?
I grow the big white ones so I'll share my experience with them, but I seem to recall that the ones with the colored flowers have a little bit different preferences, so hopefully someone who's grown them will share some advice too.
At least in my area, the big white ones don't do well when they get too much sun especially during the heat of the day. The ones I have that are the happiest are underneath my front deck and never get direct sun (although it's fairly bright shade). They don't tend to bloom during hot weather and do tend to go dormant/almost dormant during the summer. If I watered them more maybe I could keep them looking green instead of ratty, but I still don't think they'd bloom much in the summer. Mine grow quite vigorously so I have not fertilized them in the 5 yrs I've had them.