Growing Concerns 490: How late can you plant in fall

Late Fall!

Okay to Plant Perennials Until The Ground Freezes 


Dear Janet,

How late is too late to plant potted perennial stock in the fall? I know I'll have to water any new plantings until the ground freezes -- if it ever does this winter! -- and I know a good layer of mulch will ward off frost heave of late plantings with poorly established roots. But should I risk putting in plants at this late date or just winter them over in my unheated attached garage or unheated garden shed?


Dear M.,

I plant perennials in my own garden until the ground freezes and have talked to many others who do the same. The key to the plants' survival is probably not air temperature or even soil temperature but soil condition. If you plant into well drained, loose soil you'll have few losses. In beds that drain poorly or have compacted soil, any light-weight, quick-drying clumps of potting mix will be squeezed out and up during winter. The plant in that clump will dry out and die. That's why a heavy mulch is part of the late planting prescription -- if a plant does heave it will still have some insulation until you can reset it in spring.

You can also hold the plants in pots if you protect them from repeated freeze and thaw. In the ground, hardy roots are insulated by soil. Separated from the cold by just a layer of plastic, they may freeze-dry. Grouped together in the shade and covered with a leaf pile, or enclosed in a garage or shed they should escape at least some of the wide temperature swings that lead to such damage.

During winter, water is even more important to plants in pots than those in the ground. Check the pots occasionally, judging by their weight whether they are drying out. As they do, put snow or ice on the soil surface to moisten it during the next warm spell, or water the pots as they thaw.


Short reports

Let's be factual about Daylight Saving Time...

... as you continue to write to me about it!

Benjamin Franklin may have been its first proponent, but that was a jest in a 1784 essay "An Economical Project." He poked fun at himself and all Parisians who, he said, never rose before noon. His calculations indicated six hours of sun wasted per day meant Parisians used 64,050,000 extra pounds of candle wax each year. He made merry with the thought, proposing cannons be shot at dawn and shutters on windows be banned to encourage earlier rising and fewer candles burned.

During the first World War, European countries acted on the idea to save on fuel needed to generate electricity. The U.S. enacted DST in 1918 at the same time it instituted standard time zones to end confusion in train schedules. DST was repealed in 1919 due to popular demand but reinstated nationally year round during WWII. That ended after the war, though some States opted for DST in summer.

In 1966, a Federal law set fixed dates for the beginning and end of DST, if used. This was in response to requests from broadcast companies and others who had trouble with varied dates for the change across the country. In 1973-74 during the Oil Embargo we went to year-round DST for 15 months, to save the estimated 300,000 barrels of oil per year used to generate electricity for an extra hour each evening.

Discard that notion, those of you who wrote, that DST had something to do with allowing gardeners to work longer in their Victory Gardens. And to those who claim it was enacted for the benefit of farmers, just listen and you'll hear guffaws ringing across the countryside. Farmers and others tied most closely tied to sunup and sunset have always been opposed to DST. Take it from M.N., a Canadian poultry farmer who wrote, "Chickens do not adopt the change for several weeks, so the first of April and end of October are very frustrating."

Trim those overgrown evergreens now...

... to make a pretty and soil-friendly cover for otherwise bare annual planting beds. The crumbly soil you worked so hard to attain will otherwise be pounded by winter rain and its components separated to leave lightweight clay on top. So prune those shaggy shrubs and layer the clippings over the bed, newest tips showing. That's color and fragrance for you and a shock absorbing blanket for the soil.


Green thumbs up

to J.M.  who is trying to make her gardening simpler by growing only plants so well suited to her site they will thrive without fussing. This means giving up species she has been growing but has to baby to keep alive. Given a gardener's urge to collect, that's tough to do, yet she reports progress, saying, "I've given away a lot of plant material and I'm getting better at it!"


Green thumbs down

to razing the garden for winter. Making a moonscape of what was colorful and drew your eye for eight months is a quick ticket to the melancholy of Seasonal Affect Disorder! When you clean up, first remove or cut down only the plants that will shatter or turn to mush over winter. Leave plants of substance. Then look over the composition and cut out or add to make it more pleasing.


Originally published 11/16/02