Ron Kujawski | Garden Journal: We needed the rain, but not like this ...
After a lengthy period of sparse rainfall, it seems the bottom fell out this past week as we experienced one gully washer after another.
At first I welcomed the precipitation, but I preferred it come as a steady and less pounding rain over the span of a day or two. Admittedly, most plants in our landscapes and gardens are benefiting from the much-needed moisture. However, where bare soil exists, these heavy downpours have the effect of altering soil structure. Even on gentle slopes, there are clear signs of soil erosion with very fine soil particles having moved down slope and accumulating in the slightest depressions. This does alter the physical structure of soil, leaving behind slopes devoid of some of the silt, clay and fine organic components essential for holding plant nutrients and moisture. The very fine particles that accumulated downslope or in depressions will, upon drying, form a crusty layer, which affects the future movement of water and oxygen into the root zone of plants growing there.
So, now what? To start with, avoid traversing saturated soils, whether it is in the lawn or gardens, as much as possible. Repeatedly walking over these areas will lead to soil compaction and, subsequently, poor plant growth. Such avoidance is easier to do with respect to lawns where there is usually a walkway. However, we are harvesting peas, lettuce, broccoli, raspberries and other crops daily and that necessitates that we walk over the garden soil. To ease the potential for soil compaction at least a little, I've been applying straw between rows of plants where we walk. In some rows, I scattered empty pods from shell peas.
In fall, the dried pods will be tilled under, adding organic matter and nutrients to the soil.
Where there are bare slopes prone to erosion, plant a ground cover of some sort. There are many options, ranging from creeping types, such as pachysandra (preferably the native Allegheny pachysandra) and creeping phlox, to native grasses and wildflowers, or even shrubbery, e.g. creeping juniper. Be sure to work some organic matter into the soil before planting and applying a mulch afterward to reduce the chances of further erosion while the plants are getting established.
There are two other immediate concerns regarding frequent and heavy downpours. One is the leaching of nutrients from the soil. As mentioned last week, this is an important time to be applying fertilizer to long season crops. This is even more necessary as rains persist. Finally, and most importantly in the vegetable garden, there is an increased potential for plant disease. For example, infections of early blight disease of tomatoes often occur as a result of rain splashing contaminated soil onto the plant foliage. The potential for this and many other diseases may be reduced by maintaining a cover of mulch over the soil and by pruning or thinning to increase air flow around the plants. Also, an application of a bio-fungicide, such as Serenade, containing the bacterium, Bacillus subtilis, can help in preventing plant disease.
CHORES ABOUND DESPITE RAIN
Well, as I write, it looks like more rain is imminent. All I can think of at the moment are these lyrics from a Creedence Clearwater Revival song:
Still the rain kept pourin'
Fallin' on my ears
And I wonder, still I wonder
Who'll stop the rain?
I don't know who'll stop the rain, but it won't stop me from listing some gardening tasks for the week:
- Place a layer of poultry grit or pea stone over the surface of potting soil to prevent heavy downpours from washing out the soil around the plant or plants in the pot. That's a lesson I learned through trial and error, mostly error.
- Save egg shells. Dry the shells in a paper bag and then crush them by rolling a rolling pin over the bag. Spread the crushed shells around the base of plants prone to attack by slugs and snails. Though I haven't tried it, scattering coffee grounds on the ground around plants is also supposed to deter slugs. Perhaps a mix of coffee and crushed egg shells will work even better. Anyone up for a breakfast of scrambled eggs accompanied by a pot of fresh brewed coffee? The benefits are many, but not always obvious to non-gardeners.
- Hill up leeks when the white portions of the shoots are visible. Mound soil just to cover this portion of each plant. Continue to hill whenever more of the white part of shoots is seen.
- Check spinach, chard and beets plants for signs of leaf miner. The first symptom is the presence of a narrow light-colored winding trail or blotches on the leaves. Peeling back the blotch will expose a pale, white maggot. Tear off affected leaves. Placing a floating row cover over the plants will keep the adult flies from laying more eggs on the leaves of these crops. Spraying plants with neem oil is also an effective and organic method of control.
- For a sweet-scented shrub, plant a swamp azalea (Rhododendron viscosum). This is native of eastern U.S. prefers moist, acid soil and is in full bloom now.
- Cut back annuals that have bloomed and are looking a little tired now. Apply a water-soluble fertilizer to give the plants a boost for the next round of flowering.
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