Soil improvement, prep and fertilizing in April

$You can clean up all old vegetation left in a vegetable garden.  Just be careful not to walk on soil that is still very wet as you will compact it and make it much harder for plants to grow in later.  Make sure you remember what crops were planted in what areas last year, so you can rotate your crops this year. You can slowly and carefully remove mulch placed around plants to protect them as the weather warms.  Many gardeners leave it nearby to be quickly raked back over plants if a hard freeze threatens.  Be careful not to damage the growing shoots of plants as you rake beds.  If debris such as straw mulch, shredded bark or leaves isn’t too thick and matted it can just be left to decompose and add organic matter to the soil.  While this may look a little messy in early spring by the time we have a few warm rains and plants get growing it will disappear and be good for your soil.  Really thick mats of leaves or straw should be loosened or partially removed.Here’s a tip about mulches.  While mulch is great to keep plant roots and soil cool and moist in the summer, it also keeps soil cold and wet in the spring, when those conditions may not be ideal.  Rake back mulch from areas where you want to plant early crops to let the soil warm and dry out a bit.  And don’t add mulch to most beds until the soil has warmed a bit.  If the soil is dry, moisten it before adding mulch.  Letting the soil have some sun early in the spring may also help destroy some fungal disease spores and keep pests like slugs from getting a head start.All old dead annual flowers left in a garden can be removed.  Be a bit more careful and slower removing dead parts of perennial plants.  With plants that re-grow from the crown or roots each year such as hosta, daylilies, hibiscus, echinaceas and so on you can carefully remove dead plant parts left through the winter.  Be very cautious removing dead chrysanthemum foliage, the new shoots are at the base of the old and easily damaged.   Cut rather than pull off the dead foliage.   You can mow or burn off the dead blades of ornamental grasses.  (Be very careful with any fires in early spring as it is often dry enough to cause brush and field fires.)With woody perennial plants, plants that typically re-grow buds along old stems each spring, there may be some winter die back of the tips of stems.  Wait until the weather is warm enough that you can see the new green buds along the stems before you prune off what you suspect is dead wood.  Then prune the stems back to just a ½ inch above a green bud, so you don’t leave dead stubs.   Of course if you want the plant to be smaller this year you can prune it back to a ½ inch above any bud at the size you want it to be.  Any plant that has early spring blooms such as forsythia, redbud, flowering quince, lilac and so on should not have any pruning done until after the plant blooms, if you want spring bloom.Wait to prune evergreens, such as pine or spruce, until new growth has started.  Then do not prune past the last green bud on a branch.  Oaks should not be pruned after sap has started flowing, as this encourages a small beetle to spread a fungal disease that can kill them.  Fruit trees should be pruned before the buds swell also, but you can still trim off water spouts, thin branches that grow straight up along trunks and inner branches and any sprouts that pop up through the ground from the roots.If spring bulbs have bloomed remember that the foliage needs to be left until it dies down naturally if you want flowers again next year.  $
$April is a good time to plant grass seed in zones 4-6.  Grass likes cool, wet weather for germination.  Even a little snow won’t hurt it.  But do water it if spring is dry.  If piles of snow lingered a long time or puddles of water sat for many days you may have dead areas on the lawn which will need to be re-seeded.  If your lawn is up and growing mow it when it gets about 3 ½ inches long and only remove about a ½ to ¾ inch or a third of the grass blade at a time.  This keeps the grass green, healthy and dense.April is also a good month to fertilize lawns in zones 4-6.  Apply 3 pounds per 1,000 square feet of a high nitrogen fertilizer, generally labeled lawn fertilizer. (Nitrogen percentage is the first number on a fertilizer bag.) Follow the label directions.   Some fertilizers also contain weed killers or preventers, such as crabgrass preventers.  Lawn grub control tip.  Some fertilizers also contain grub or insect controls. Do not apple these products unless you know you have a grub problem.  However, in zones 4-6 grub control products containing imidacloprid, thiamethoxam,or halofenozide will not work to control grubs in the spring, regardless of what the bag says.   By the time summer comes when they would work, their effectiveness has greatly diminished if applied in April.  Apply these products in June or July for better results.  Products containing chorantraniliprole can be applied now but won’t work until later in the summer. Read the label to find out what ingredients are in the bag.If you feel you have a bad grub problem in early spring, because you can actually see grubs at the grass roots you can apply a product that has carbaryl ( Sevin) and/or trichlorfon as active ingredients.  They will reduce the grub population but aren’t as effective as applying the correct product in June and July. Michigan State University turf experts say that these products; lambda-cyhalothrin, gamma-cyhalothrin, bifenthrin, deltamethrin, cyfluthrin or permethrin do not kill grubs, although they may kill other insects on the soil surface.Remember that all pesticides can kill good as well as bad insects and other organisms such as earthworms.  They can also be harmful to children and pets. Don’t use pesticides unless you absolutely have to, and then use them only as directed on the label.  Don’t buy fertilizers with pesticides included “just in case.”  You’ll save money and the environment.$

Photo: Kim Willis

Soil improvement, prep and fertilizing in April

April is a good month to fertilize trees, shrubs and perennials. Use a slow release fertilizer, following label directions, preferably just before a rain. You can apply the fertilizer even if the plants haven’t begun growing. Do not add manure to vegetable gardens in the spring to avoid any chance of E.coli or other soil borne organisms causing illness. Add it in the fall. Compost can be added after the ground has thawed and warmed a bit. A light layer of compost can be added to lawns as they begin to grow.

Have your soil tested early in the spring if you have never had it tested or it’s been 5 years or so since it was tested or you suspect a soil nutrient problem. You will then have time to correct the problem before planting. Don’t add lime to any garden unless you have the soil tested first and find that it needs it. A vegetable garden can have a good slow release fertilizer (choose one for vegetables) worked into the soil before planting.

Stay out of the garden if the soil is too wet. No digging, no rototilling or even walking on while the soil is wet. This will cause soil compaction and ruin your soil for many years. Your soil is just right when you grab a handful, squeeze, then open your hand and it crumbles apart but still feels moist. If it stays in a clump it’s too wet to work.

A tip about tilling. Don’t over till your soil. Too much tilling ruins the structure of your soil and destroys beneficial organisms in the soil. If you are breaking ground for the first time two passes of the rototiller may be needed. Previously tilled ground should never need more than one pass with the rototiller. Double digging is now thought to be unneeded and potentially harmful too. If you have good loose soil in a raised bed you might not need to till or dig the soil at all. And April is a great month to make and fill raised beds.

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