What are the regular routines for the Landscape Gardener to maintain the home grounds in the best condition going into winter?
Watering: There is much debate over what the autumn to late autumn watering schedule should be for the Twin City area landscaped grounds. Some ‘professors’ profess continued regular watering until the hard frosts; others suggest withholding water gradually to assist the plants hardening off for the cold misery of winter. Plants here usually mean woody plants.
Not all plants are equal. Herbaceous perennials are much more ephemeral in the grounds than cold tolerant trees and shrubs. Not all autumns are equal either. This passing October was wet at first and then decided to move into a beautiful season of cool, sunny, colorful, gorgeous and DRY Minnesota autumn…..going waterless on almost three weeks now….and I think it is great even though I have had to use the sprinkler since I had my irrigation system winterized early this year.
In this case I believe watering the shrubs and trees about every fourth day at twenty minutes or so a spot, during such a period would be enough. Soil type can be a factor if you are unlucky enough to garden over soil of heavy clay. Sandy soils are much easier to manage with watering……less intensity but more frequency than normal. Clay soils which have not dried out during the heat of summer to brick, don’t need to be watered much in the autumn regardless of the temperatures. Hot, dry October winds might cause some reconsiderations.
October temperatures are cool. Heavy watering can be damaging to some conifers which become shaded with the sun ”falling’ toward the horizon here in our Northland. Foliar disease are especially ravaging on Colorado Blue Spruce. Others damage tree yews. Symptoms most observed are the withering of the interior older foliage. Yews begin to lose their yellowing needles in late Spring. Blue spruce will show a gray to brown sickly dried up crop of old needles and be dropping them about now. One of my white pines has a foliar disease similar to these.
Shade, moisture, and lack of air movement to dry off the foliage reliably, are the collective causes of the unsightly disfuguration to many of our conifers.
Should hostas and other perennials be pruned back in fall or spring? I grow hostas because they offer an artistic plus to my grounds, not because I am a hosta guru. My entire grounds is a landscape garden. Not all hostas are equal. Some hold attractive foliage into very late autumn and others don’t. Some are less hardy than others. I cut back foliage on those whose foliage no longer please me IF I have time to do this clean up.
However, there is one note which must stand firm and deeply in the Minnesota landscape gardener’s understanding of the onslaught of winter upon cherished garden plants, woody or not…..
The greatest threat to Minnesota landscape garden plants is the autumn disaster of temperatures dropping below ten below zero or more, Fahrenheit, before Thanksgiving, and anything around twenty below zero before Christmas WITHOUT snow.
Snow is nature’s best insulator for outdoor plants. The second best is certain kinds of leaf cover…..namely the kind called oak leaves. Others may work or may cause additional troubles to garden plants. I let oak leaves go where they may in my autumn garden.
Oak leaves are crinkly and don’t break down rapidly even despite wet weather. They create air pockets over whatever ground the manage to cover. If the gardener waits till Spring to cut back dead perennial foliage, the plant will be somewhat better protected through a snowless frigid spell when leaves of any kind are captured by any plant “stalks”.
I am the only groundskeeper of my landscape grounds. Time available usually dictates my scheduling for manicuring the fall garden.
Two years ago I lost four spreading yews and one twenty foot upright yew to winter kill. The plants were in the garden for over fifteen years. There was plenty of snow cover. However, sometime in January over a weekend when the temperature had dropped to minus 10 degrees Fahrenheit, there was a steady thirty mile an hour wind from the North for two days. A good friend in Waseca, Marian Fischer, was certain her similar losses were due to that January windstorm.
There is always the unexpected.
Major pruning of woody plants should wait until Spring, the earlier, usually the better. The more one knows about pruning, the more one can safely disobey this recommendation, however.
Ideally, pruning of apple, crabapple and pear trees should be done in late February or early March, to avoid the spread of the bacterial disease called “Fireblight”.
So many special plants now growing in our more up-to-date landscaped grounds may require exceptional treatment for winter care for which we have no reliable information except for our own observations.
Those of you who live in the center Twin Cities and the immediate suburbs are now living in horticultural zone FIVE……. My ideal garden zone. Where I live, west of Minneapolis, I can grow many zone five plants but I have be call my area, zone four and a half.
Zone Five Japanese Beetles visited my grounds for the first time in known history this past summer. One has to take the bad with the good if one is a devoted Landscape Gardener……And Japanese beetles are not good…..but if that is what it takes to get a little Global Warming to reach Zone five, I’ll accept it.
Many who live in the city have a serious rabbit and mouse problem…..especially in grounds surrounded by entrapping fencing. Trap and kill, most serious landscape gardeners recommend. Chicken wire fencing around the most susceptible plants such as Winged Euonumous or some of the Viburnums. Some tender gardeners trap and relocate…..but that can go on for weeks and months.
I will recommend nothing here. It is your call, dear fellow landscape gardener.