April gardening tips

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.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.  On those rainy April days when little else can be done its time to clean and oil your garden tools, paint tool handles a bright color so they can be seen when you lay them down.  Sharpen blades on pruners and saws or buy new pruners and saws.  Inventory your tools and see if you need to shop for new ones while the selection in stores is still good.   Make sure you have a good pair of garden gloves too.Start up the mower and rototiller if you have one.  Get mower blades sharpened or replace them.  If the mower needs to be repaired or replaced now is the time to do it, before the spring rush causes long delays in repair time and the best selection of new mowers is gone.Buy supplies of seed, fertilizer, planting soil, mulch, fencing, and other project materials so when the weather is right you aren’t standing in line at a garden store instead of being in the garden.View the list »
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April can be a tough month for gardeners. After a long winter the signs of spring that April generally bring get our gardening juices flowing. But for northern gardeners at least, April is a month for cautious gardening, as the weather can be very fickle. It can be 80 degrees one day, sunny and humid, and 35 degrees with snow flurries the next. This spring of 2013 is starting out slow and cold, with many planting zone 4 -7 gardeners still struggling with snow on the ground and frozen soil. But there is still some gardening that you can do in April and it’s a good month to prepare for May, generally the most frantically busy of months for gardeners. In the South, zones 8 and higher, spring is pretty advanced and planting is probably in full swing.

This article is going to refer to planting zones. The USDA has a map that divides the country into “zones” for winter hardiness of plants. The zones also tend to have similar temperature patterns so when we discuss gardening such as what to plant when; we have a general starting point for different areas. We can say that in Zone 5 its time to plant grass seed for example. You can see the USDA zone map at the link at the bottom of the article if you don’t know what planting zone you are in and there’s a link to an article that explains planting zones a little better there too.

While planting zones give a general idea of your climate, each gardener also has “microzones” to deal with. Microzones can be the warmer area near your foundation or in an alcove or courtyard. Cities often are a bit warmer than open country. And there are frost pockets or cooler areas too, you can often notice these places in April as the places where snow still lingers or the ground is still frozen. Low, wet areas tend to stay cooler than high, well drained areas. Each gardener needs to learn the microzones on his or her property and learn to use them appropriately.

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  • On those rainy April days when little else can be done its time to clean and oil your garden tools, paint tool handles a bright color so they can be seen when you lay them down.  Sharpen blades on pruners and saws or buy new pruners and saws.  Inventory your tools and see if you need to shop for new ones while the selection in stores is still good.   Make sure you have a good pair of garden gloves too.Start up the mower and rototiller if you have one.  Get mower blades sharpened or replace them.  If the mower needs to be repaired or replaced now is the time to do it, before the spring rush causes long delays in repair time and the best selection of new mowers is gone.Buy supplies of seed, fertilizer, planting soil, mulch, fencing, and other project materials so when the weather is right you aren’t standing in line at a garden store instead of being in the garden.
  • 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 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.
  • 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.
  • Now is the time for gardeners in zones 4-6 to go full steam ahead with seed starting inside of those garden plants and flowers.  Start seeds inside about 6 weeks before you would normally plant them outside in the garden.  That would be beginning in early April for zone 7, maybe 6 and mid to late April for zones 4-5.  This would include tomatoes, peppers, cabbage, marigolds, zinnias, and many other plants that are planted out after the danger of frost has passed or where you want them to mature before summer ends.  Read the seed starting articles on the links at the end of the article.One exception for starting seeds inside is for those vine crops which are difficult to transplant when they get large.  That would include melons, pumpkins, squash and cucumbers.  These should be started only 3-4 weeks before you would generally plant them in the garden. In zones 5-7 lettuce, chard, beets, and other greens can be planted in cold frames outside or under plastic or fabric hoops.  Peas can be planted in the ground as soon as it thaws in all zones, without any protection.Some zone 4-6 gardeners may want to start the bulbs of canna’s and dahlias inside about the last week of April. This will make sure that the plants will be mature enough to bloom before the fall frosts.  Pot them in good potting soil, place them in a sunny window with temperatures above 60 degrees and keep them watered.  Plant outside after all danger of frost has passed.  Planting hint; if you use generous sized pots you can simply sink the pot in the soil outside, which will make the bulbs easy to harvest and store in the fall.
  • Any dormant plant can be planted as soon as the soil is thawed and not too wet as to compact when worked with or have standing water in a hole.  A dormant plant is one that hasn’t got new leaves or big swollen buds yet.  This includes trees, roses, strawberries, other fruit plants, and dormant bare root perennials.  Most evergreens can be planted outside now too.  For early color you can plant pansies and violas, which can stand frost and even a little snow.  Most garden centers have them in April.Perennial planting tip- when you go to a greenhouse or garden center in April you’ll find many perennial plants that are already growing, maybe even blooming.  Because barely growing plants don’t have as much appeal to buyers the perennials are shipped in from the south or from a greenhouse.  But if you take these plants which are weeks ahead in growth stages from plants in the ground and plant them outside in April in zones 4-7 the plants may experience shock, die back, or total loss. Plant growing perennial plants outside when the same type of plants have begun growing outside in your area.  For example plant that pretty new hosta outside when you see new leaves unfurling from your old hosta.  The plants outside don’t need to be as developed as the potted plant but they do need to be actively growing. If you must buy perennial plants that are way ahead of plants growing outside in development, plan on protecting them with covers on cold frosty nights.Remember when buying blooming perennials in early spring that they probably won’t be blooming at this time next year when planted outside.  And if you are combining colors that look well together in the garden shop realize that they may not bloom in the garden at the same time when planted outside. Most annuals and tender perennial bedding plants can’t be planted outside until after the last frost.        (Coleus, impatiens, begonias, marigolds and so on.) That won’t happen until May at least for zone 4-7 gardeners.  If you buy the plants now and try to keep them inside it will be a hassle and you will probably lose some.  Garden shop owners know some people will buy them anyways, and then have to re-buy them later. Let the greenhouse care for them for a few more weeks and save your money.
  • Mail order plant sellers try to guess when conditions are right to ship plants to your zone, but they sometimes guess wrong.  If the plants are potted and leafed out you will have to find a sunny windowsill for them until the ground is thawed and the weather has warmed a bit.  If they aren’t potted but are leafed out plant them in good potting soil and place in a sunny window.Dormant plants that arrive when the ground is still snow covered and frozen are a bigger problem. Open the packages, remove any plastic, and keep any packing such as shredded paper or peat around the roots moist.  If they don’t come with packing you can tear paper in strips and moisten it to wrap the roots.  If they are potted and dormant keep the soil in the pot moist.   Store them in a cool place.  Do not sit them in a bucket of water.  If you think that you will need to hold them for more than a week it is best to pot plants in good potting soil and sit them somewhere cool but freeze free.  A garage or unheated porch may work.  Don’t worry about light unless they begin to leaf out, then they will need good light.  Plant dormant stock outside as soon as the soil thaws, they can take the cold, before they leaf out if possible.Bulbs will generally keep in a dark cool place in the shipping material until you can plant them.  Open up any plastic bags to vent excess moisture.  Packaged, bare root roses will keep in the package in a cool, dark place for a couple weeks. Strawberries that arrive bare root and bundled in a bag can be wrapped in a moistened paper towel and stored in the crisper drawer of the refrigerator.  Check them every day to make sure they are moist, but not moldy. If mold develops spread them out and let them dry slightly.  Plant them outside as soon as possible.  If you have concerns about holding plants call the garden store you purchased them from and ask for advice.Before you know it April will be over and the garden season will be in full swing.  The weather will hopefully be great and you will be ready to hit the ground planting.  Here’s those links I promised. USDA  map with interactive features http://planthardiness.ars.usda.gov/PHZMWeb/ Starting seeds indoors http://www.examiner.com/article/tips-for-starting-seeds-indoorsSeed starting http://www.examiner.com/article/what-you-need-to-know-about-seed-starting-soil-or-mediumLawn care http://www.examiner.com/article/april-lawn-care-for-michigan-gardenersSmart planting tips http://www.examiner.com/article/smart-planting-tips-and-trickIf you would like to sign up for the authors free weekly email garden newsletter please write to kimwillis151@gmail.com 
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, Detroit Gardening Examiner

Kim Willis lives near Clifford, Michigan on a small farm that she shares with her husband and numerous animals. She works at the Lapeer County MSU Extension office and is a freelance country and garden writer. Her book Complete Idiots Guide® to Country Living was published in November 2008. Her...

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