Might sound like a strange question, but I have about 50 hostas that I planted in a place that has had constant moisture for years until lately. Question is what is the minimum amount of water I can use to keep them alive? Problem is we have a well, and I don't want to run it dry. Also, there are a couple hundred other assorted perennials that I'm trying to keep going. I've been trying to get everything as close to an inch a week as I can. Will this be enough? Its been in the high 90's, and doesn't look like any rain coming for awhile.
Hi Bruce. I'm in the same zone as you and we're on well water as well. Despite the fact that we've had the sprinkler system going almost daily, my hostas are struggling in this heat. It's not just the lack of rain but also the constant breeze that is drying out the soil. My hostas are also competing with tree roots for water. Some are crisping up that have never done this before. Mulch would help but I don't mulch except for a light layer of pine needles in some of my hosta beds because I don't want to provide a breeding ground for slugs and earwigs. I think water tables are generally lower this year because we had very little snow fall last winter. A neighbor of ours says his well water level is down 2 feet this year. One of my minis has gone summer dormant already but I'm continuing to water it, hoping it will come back next spring. It's my feeling that as long as our hostas are surviving, they're getting adequate water but probably not as much as they would like. When I see them start to droop I give additional water. Hope someone has better answers than mine.
I can't really give you a good answer, but an inch a week sounds like a good goal. Some individual hostas might need a little additional water; you can probably gauge that on a visual basis. I have a few hostas, as well as some perennials like astilbe and Japanese ferns that droop after even a day with less water than they like. Several crispified in last year's drought and heat. The ferns all came back fine, a couple hostas were stunted and came back small, and one astilbe disappeared completely.
Will an inch of water be enough? It depends on your ground and weather, etc. Will they survive on less? Maybe. But they could very well come back smaller next year, if they don't get enough water now. To have less water waste via evaporation, focus on watering early in the morning or mid evening and don't use overhead sprays that sprays too finely. I like to set a small sprinkler on low and move it between my hostas.
Thank you for your responses, and thanks Eleven for the link. I think I will try to get them an inch a week, and watch them closely for signs of crisping. And of course I will keep praying for rain!! We got 3/4" here today, so that will really help.
Gotta chime in here. Due to the extreme heat we had a couple weeks ago I also have a little burning on some leaves but I've been very impressed overall to how well my hostas have done. They really don't need as much water as you think to stay looking good. I've watered occasionally, but really haven't babied them and they still look fantastic (even the ones growing under a maple tree)
Pic was taken on July 9th, after our week of 100+ temps.