The lone voice of horticultural reason

Fall Duties I

There certainly must be falls on record as gorgeous as this one, but not in my recent memory. We have had a long growing season, and these brilliant, sunny days could easily extend far into October. This doesn’t particularly change the timing of our fall gardening duties, it simply makes them all the more enjoyable.

While planting some spring-flowering bulbs the past few days I was surprised to discover how dry the soil was in some of my beds, even six and more inches deep. A good reminder to me that perennials are enjoying this fall just as much as the rest of us, and still need water. They’re not growing as actively and of course the cooler temperatures means the beds don’t dry out as fast, but neglect perennials in October and they will be at a definite disadvantage when it comes to surviving winter. We got a little spoiled this summer by all the hard rain-I never in my life spent less time watering-so it’s important to get back into the habit of watering perennials weekly (adjusting for good, soaking rains) right up to the first hard frost.

The same goes for trees and shrubs, especially for trees and shrubs planted this year. I have a row of 12 – 7′ arborvitae in a side yard and when I come home from work I’ll turn on the hose and stick it at the base of the first one. I eat dinner and at some point 20 minutes or a half hour later I go outside and move the hose to the next one. If I’m going to be home that evening and I trust myself to remember that the hose is on, I may proceed like this for another hour so that I wind up watering four arbs for the day.

The next evening I take care of three or four more. In three or four days I’m done, and three or four days after that I’ll start over again. Obviously this summer there were a great many weeks when I didn’t bother with this regimen, but I’m certainly on it now that fall has arrived. For the trees and shrubs planted this fall, six inches of shredded bark or wood chips around the base, extending out to at least the drip line, is a must, for it will keep out the cold and extend the growing season under ground well into November.

Nothing should be fertilized this time of year, save for the bulbs we plant. You want your perennial flowers and vegetables to be slowing down and hardening off, not getting jazzed up with a sudden jolt of adrenaline. Some say late fall is a good time to fertilize trees and shrubs, but the key word here is late, meaning right before or after the first hard freeze-November, even December. The fertilizer isn’t meant to be absorbed this year, it’s to be activated in the spring. Since I fertilize my shrubs and trees in the spring, I’ve decided there is no reason to fertilize them in the fall.

We’ve already had one frost warning, which I blithely ignored, as I will ignore all frost warnings right up to the frost that utterly decimates the aboveground portion of everything in my garden. I recall my earlier days as a gardener where the first whisper of a possible frost by the 10:00 p.m. weatherperson would send me scrambling from bed, into some clothes and out into my yard, where with a rag-tag collection of sheets, towels, old bedspreads and drop cloths I’d be covering everything in sight. I think I did it five times one year.

Then a knowledgeable neighboring gardener pointed out to me that annuals in gardens near Lake Minnetonka-the closer the better, but to within two miles-are always the last to go. A 28° reading at the airport means it’ll get down to maybe 34° in my yard, a quarter of a mile from the lake, because the heat rising up from that huge body of water mixes with the nighttime air and warms it.

Sure enough, in years past my impatiens were in perfect health weeks after more inland gardeners had seen theirs die. So now I figure heck, the first three or four frosts are going to miss me anyway, when the big one comes, so be it. I was getting tired of waking up and having to retrieve sheets and towels and drop cloths from neighboring yards anyway.

Don Engebretson
The Renegade Gardener