Bending the zone for plants
Published on March 14, 2023 at 3:31pm GMT+0000 | Author: Tucker Henderson
0Gardeners should avoid committing ‘planticide’
By Bev Johnson
Master Gardener
Every gardener has committed “planticide” at some time or other. Planted an acid lover in alkaline soil, a sun lover in the shade or a plant that likes damp feet in sandy soil. Put a plant that wants “peaty” soil in regular garden soil. Or planted a zone 6 plant and expected it to live through our winters. There are, of course exceptions to every rule. Some shade plants will do O.K. in the full sun.
“I’ll grow but I won’t like it,” is what I say each year.
Some hostas, like a bit of sun and some like quite a lot of it if they have damp feet. Lilies, on the other hand seem to like mottled shade even though they will grow well in full sun. The color is usually better if they get a bit of partial shade.
Our plants do better, usually, if they are listed zone 4B to 3A. the difference is… Zone 3. A has winter temps from – 35 to -30. 4A from -30 to -25, and zone 5 A is -25 to -20, a warm winter here in the usually frozen north. By the way, this was calculated from the lowest daily minimum temperature recorded for each of the years 1976 to 2005. We may have warmed up a bit since then. There are a few zone maps that show the hottest yearly warm temps. Something to take into consideration for the gardener as well as the plants.
Now this doesn’t mean you should redo your gardens with zone 5 plants, but you may be able to get away with it if you take a few precautions. Zone 5B is -20 to -15 and zone 6 A is – 10 to -5, not gonna happen here. There are limits to zone bending.
Experimenting on out of your regular zone plants means that you WILL kill some of them. A hot, windy summer can kill the hardiest plant if you forget to water it for a few days. If the day is warm then suddenly drops to below zero, something that happens quite often here, dead shrub. Or at the very least the top 2/3rds will turn a pretty brown and start shedding needles. Uncovered plants will come out of dormancy if we get a spate of warm weather in late winter. It may just set them back or kill them outright.
There are steps you can do to grow “out zone” plants here. Mulch the snot out of them in the fall. A foot of mulch is not too much. Check your gardens for snow drifts. Plant your delicate babies there as that should be the last snow to melt. Plant them in a sheltered area. On the south side of a larger or taller plant. On the south side of a building but not right up against a foundation, especially your house foundation. It leaks warm air warming the soil and encouraging plants to pop up before the air is seasonally warm. Check with other gardeners. What out zone plants have they been able to keep growing and where? Don’t give up on a plant you really want if it dies.
Try a different spot, different soil, different light, more shelter, a different plant partner. It’s not a loss until you have tried every spot in the garden, and it still died. Then you can give up. This applies to trees and shrubs too. Some will only do well in shade and others get jaundice and die in shade.
Go kill a few plants. What the heck, it’s only money… and time.