Horticulture tips

By Tim Baker, retired MU Extension field specialist in horticulture

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    January tips

    Planting woody seeds

    A good way to propagate your favorite woody ornamental plant is to plant its seeds. Simply place them outdoors in a container, or directly in the ground. The cool temperatures over the winter will satisfy any chilling requirement. The alternate freezing and thawing will usually break open seed coats of all but the toughest seeds. Next spring, you’ll be rewarded with a new seedling to transplant into your landscape.


    Terrariums are a popular way to grow plants indoors, but after a number of years, the plants inside may overgrow the terrarium and you will need to start over. Before replanting, be sure to wash the container in hot, soapy water. Use new, fresh, sterilized soil and disease-free plants to get your new planting off to the best start.

    Winter cactus care

    During the winter, cut back on the amount of water you give your cactus plants. Water them only enough to avoid shriveling. They should be placed in full sun, but where the temperature will not exceed 65 degrees. Night time temperatures should be around 40 to 50 degrees. This will allow them to go semi-dormant, just like they would experience in their natural environment.

    Extension publications

    When planning your garden for next year, don’t forget to call your local University of Missouri Extension center. We have guide sheets which provide information on a wide variety of horticultural topics. This is also a good time of the year to get a soil test through your local MU Extension center. And don’t forget Extension for information on other subjects as well.

    Freeze-thaw cycles

    Warm winter days followed by cold winter nights create a freezing and thawing cycle that can actually push your small perennial plants right out of the soil. Be sure to check them frequently, and push them back down firmly if you see this occur. Be sure to cover with at least two inches of organic mulch to insure this doesn’t happen again.

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    February tips

    Winter bulb storage

    If you have brought bulbs inside to store for the winter, don’t forget them. Make sure they don’t dry out and are stored at the proper temperature. Check them periodically, in order to remove bulbs that have become soft or diseased. If you take good care of them, you’ll be rewarded with a beautiful display after you plant them next spring.

    Hanging vegetables

    When planning your vegetable garden this summer, you might consider planting a few vegetables in hanging baskets to place on your porch, deck, or patio. Bush cucumbers, small tomato varieties, or even lettuce or greens can be grown in small containers and hung at a convenient height. Many herbs, including chives, parsley and thyme are also well-suited to baskets.

    Pruning neglected fruit trees

    Pruning fruit trees which haven’t been properly cared for can be a challenge. Spread your work out over several years, in order to discourage excessive growth and injury to large limbs due to too much sunlight. The goal is to gradually lower the tree height to a manageable level, removing surplus scaffold limbs, and eliminating weak, damaged, and dead wood. If you take your time, you’ll eventually be rewarded with a strong, healthy fruit tree.

    Nursery stock

    If your landscaping plans include shrubs, think about ordering them soon. Bare root deciduous shrubs should be planted when still dormant, around one month before the date of your average last frost. Hardy container-grown and balled and burlapped shrubs can be planted anytime, except during severe, cold weather.

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    March tips

    Timing of fruit tree pruning

    The best time to prune fruit trees is right before they bloom, but while they are still somewhat dormant. Be sure to remove dead, diseased or damaged wood. Also remove shoots which either grow straight up or down, since neither bears fruit to any great extent. Limbs which cross over in front of other branches should also be taken out, to open the tree up for light and air circulation.

    Peat pots

    If you use transplants grown in peat pots, be careful that the peat material does not stick above the soil line. With some plants, such as tomatoes, simply bury the entire peat pot and some of the stem. Some plants, however, should not be planted so deeply, so be sure to remove any part of the peat material which sticks above the soil. The reason is that any part of the peat which sticks above the soil line may act as a wick and draw moisture up and away from the plant.

    Sunscald on new trees

    When planting new trees, it’s best to orient them in the same direction that they grew in the nursery. Bark which grew on the south side of the tree in the nursery is well adapted to full sun. If you were to plant the tree in the opposite orientation, the more tender bark from the north side of the tree might not do well when suddenly faced with strong sunlight. Planting it the same direction will give more favorable results. If you’re not sure, wrap the trunk in a light-colored tree wrap for the first year.

    Early cannas

    If you would like to encourage your cannas to bloom early, simply plant them in a container in a warm cellar or enclosed porch. Use a sandy, well-drained soil mixture. Cut each rhizome into pieces containing several buds or “eyes.” After you are well past the last frost date in your area, you may transplant the developing plants outside, for an early bloom.

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    April tips

    Planting holes

    When planting a tree or other woody plant, it’s generally best to use the same soil that you dug out of the hole to put back in around the new plant’s roots. Don’t add organic matter to the soil. In heavier soils, this is especially important. You could actually create a “bowl” that holds water, and the root zone could become waterlogged in wet weather.

    Blueberry soil pH

    If your blueberries are not doing so well, you may want to have a soil test performed to check the pH. Blueberries need an acid soil, from around 4.8 to 5.2. Through the years, the soil pH may creep upwards, and after a point, this will bring disease and eventually death to the plant, if it gets high enough. pH is easily lowered with sulfur, but it’s always best to get a soil test first to make sure that is the problem, and to see how much sulfur to add.

    Vegetable garden planning

    When planning your vegetable garden this spring, be sure to allow for plenty of sunlight. If your garden gets partial shade, plant leafy vegetables in the shadier areas. They need at least 6 hours of good sunlight to do well. Other vegetables, such as tomatoes, squash, eggplant, and peppers need at least 10 hours of full sun. Be sure to plant them in the parts of your garden that get the most sunlight.


    Looking for an interesting herb to try in your garden? Try lovage. This is a hardy perennial plant with a sharp, but sweet, celery-like flavor. Leaves can be added sparingly to soups and salads. Stems can be blanched or eaten raw, and seeds can be added to candies, bread and cakes.

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    May tips

    Rainfall measurement

    Water needs in your garden can become critical in the summer’s heat, especially here in Missouri where droughts can linger for weeks. Be sure that your garden gets around one inch of water per week, from April till September. You may also want to buy an inexpensive rain gauge to place in your garden. That way you'll know exactly how much rainfall you are getting, and how much water you’ll need to add.

    Potted plants

    If you move your potted plants outside for the summer, remember that they will usually need more water than they did inside your home. This is because increased air circulation due to wind will increase transpiration and water loss. Even if a plant can take sunlight in its normal setting, it’s best to find a shadier spot at first, in order to acclimatize the plant to the great outdoors. Depending on the species, you may then move it to a sunnier location later.

    Clay pots

    Clay pots are a traditional container for potted plants, and work well. But watering requirements for plants in clay pots will be different than plants in plastic pots. This is because some water loss can occur through the sides of the pot itself. In a windy outdoor setting, you can reduce water requirements by setting the clay pot into a close-fitting plastic pot, or by covering the clay pot with aluminum foil.

    New transplants

    One of the more common mistakes with newly transplanted trees and shrubs is to give them either too much or not enough water. This is especially critical during the first year after they’ve been transplanted, since the plant must grow new roots for water and nutrient intake. When starting out, it's best to water frequently, with less water, so that your tree’s water needs are in balance, and that you don’t drown them or dry them out.

    Southern peas

    Southern peas are a favorite garden vegetable in the South, and do well in our hot Missouri summers. When growing them, remember that they don’t require a lot of fertilizer, compared to other vegetables. If you over fertilize them, the extra fertilizer will encourage excess vine growth, and will delay pod set. Be sure to harvest ripe pods, once they are fully formed. This will encourage the plant to continue producing more pods.

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    June tips


    Okra lovers can extend their harvest season two ways. First, they can plant a second crop later in the season, giving young plants to harvest from as the summer progresses. Another method is to cut back part of your okra patch to several feet above the ground, after they get too tall. If done at the right time, and if watered sufficiently, the plant will re-grow, providing you with another crop of delicious okra before summer’s end.

    Heirloom roses

    If you enjoy roses, but don’t have the time it takes to properly take care of the traditional hybrid tea roses, try some of the heirloom rose varieties. While not as showy as they hybrid tea roses, many of the antique roses require much less maintenance, and many are resistant to the common diseases that plague roses in our area. Ranging from bush types to climbing varieties, there’s an heirloom rose to please any taste.

    Spraying gardens

    When it’s time to spray your garden for insects or diseases, here are a few tips that will help. Generally, don’t apply spray to the point that the plants are drenched and dripping. They just need a fine, even mist. Remember to spray when it’s calm. Wind will carry the spray to places you may not want it, injuring other plants, people, or pets. Finally, always follow label directions and use protective clothing. It’s better to be safe, than sorry.

    Storing potatoes

    When the time comes to dig up those Irish potatoes you’ve grown this spring, you will need a good place to store them. Be sure to keep them in a cool place. The cooler you store them, the longer they will last. Allow for good air circulation. Don’t pile them too deep. Finally, keep them in the dark. Potatoes will develop a green color if stored in the light, and bitter tastes may result.

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    July tips

    Fourth of July tomatoes

    Do you want vine-ripe tomatoes from your own garden for that Fourth of July backyard BBQ? That can be a challenge in colder climates, but with the right varieties and favorable weather, you might be successful. Look for quick-maturing, short-season varieties. For example, there's one that's actually named Fourth of July, which is said to ripen within 49 days of planting.

    Mulching for water conservation

    It's rare that a summer comes along that doesn’t have a few dry spells to stress your garden. To save water, and the time spent applying it, consider putting down a good mulch. This greatly reduces evaporation from the soil. Be sure to pull back the mulch before you water again, to see how moist the soil is. You may be surprised to see how much moisture is still there.

    Mulching for weed control

    Weeds are the perennial foes of all gardeners. They compete for water, nutrients, light, and may even harbor diseases or insects which can infect your garden. Instead of applying chemicals, which may harm your garden, consider a good mulch. You’ll need enough to keep the light from reaching the soil surface, and allowing those dormant weed seeds to grow.

    Emerald ash borer

    Unfortunately Missouri now has several areas where the Emerald Ash Borer has been found, including many locations in the Kansas City area and Northwest Missouri. This insect has been a real problem in some states, taking out ash trees in many acres of forest. If you find any of these small metallic green beetles, give us a call for a positive identification.

    White grubs in lawns

    White grubs can be real pests in lawns. They eat on the roots of your grass, causing it to thin, wilt, and dry out. It may look like a drought, even if you water your lawn or get rainfall. They may even attract birds, moles, or even skunks or raccoons that may dig up your lawn in search of food. If you have white grubs, call your local Extension center and ask for our guide on how to control them.

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    August tips

    Fall frosts

    Fall vegetable gardens are a great way to keep fresh vegetables coming until the first frost. By planting in late summer, you will have new, vigorous plants well-established when fall arrives. Be sure to allow plenty of time for the crop to mature. Average first frosts run from Oct.10 to Oct. 15 in northern Missouri.


    Composting is a time-honored way to create a nutrient-rich soil amendment that will help your garden grow. It also is a good way to deal with organic plant material that might otherwise create a waste disposal problem. Think about all those fall leaves that you rake up every year. What better use than to put them to work in your garden! If you would like to construct a compost bin, give us a call for a guide sheet that will help.

    Spider mites

    Hot, dry weather brings on yet another pest in your garden. Spider mites are not true insects, but they can do a lot of damage in short order. They can attack vegetables, fruits, and even ornamental trees and shrubs in your yard. There are chemical controls that can help. Give us a call for recommendations.

    Pruning trees

    I’m often asked what time of the year is best to prune trees. Normally, it will be in the dormant season, in late winter. But if you have storm damage, trees that are a danger to life or property, or trees that are just in the way, summer is an acceptable time to prune them. If you need guidelines on how to prune your trees, give us a call for a guide sheet on that subject.

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    September tips

    Potted plants in hot weather

    If you have potted plants outdoors, be sure to keep them well watered in hot weather, especially if they are in the full sun. You may need to water them daily, depending on the type of soil in the pot. But don’t overwater. The soil should not be soggy or have standing water on top of it. Be sure the pot is well-drained. Clay pots allow evaporation from the sides, so be sure to check them more often.

    Fall fertilization

    Be careful about fertilizing trees and shrubs in the fall. Generally it’s not a good idea except under emergency conditions. If you feel you must fertilize your trees or shrubs, try to wait until the leaves have fallen before doing so. Fertilizer added while the leaves are still active promotes succulent growth which has great potential for winter damage, and thus should be avoided.

    Spring garden beds

    Now is a good time to think about preparing new garden beds for next spring. As you till the soil, add plenty of organic matter such as leaves, and leave the surface a little rough so water will penetrate. You should also get a soil test to see if you need to add lime. Then plant a hardy cover crop, which will grow this fall and early next spring. When you are finally ready to plant next year, till the cover crop in and you’re ready to go!

    Cool season grasses

    The best time of the year for planting cool season grasses, such as fescue, is in the fall. This allows time for the grass to become established before winter sets in, and then additional time to continue growing next spring before the heat of summer arrives. If you need a good grass for shady areas, you might consider creeping red fescue. Plant it in later September and you’ll be rewarded with a good lawn under your trees next year.

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    October tips

    Fall vegetable watering

    Fall can be a good time for growing vegetables, but don’t forget the water. Although you plants may not need as much water as they did in the heat of summer, they will still need adequate water to mature properly. Since fall in our area is sometimes dry, you will need to remember to check your garden often and water when needed.

    Cold weather hardening

    As we approach winter your trees and shrubs will begin to harden off in order to withstand the cold weather ahead. If you have mulch around them, it will help the hardening off process to remove the mulch for the fall. This will encourage the plant to go into dormancy. When the plants finally do go dormant, replace the mulch for protection through the rest of the winter

    Leaves as mulch

    When the leaves begin to fall from your trees don’t overlook ways to use them in your garden. Instead of burning or discarding them, use them in a compost pile to provide nutrients for next year’s garden. Or, grind them up in a shredder to use as mulch. When shredded they won’t compact or blow around, and allow good water penetration to the soil.

    Fall garden cleanup

    One important fall gardening activity that is easy to forget is the fall cleanup. This is important to the health of next year’s garden because many diseases can overwinter in the roots of perennial weeds. Examples include tomato mosaic virus, cucumber mosaic virus, bean mosaic virus, and many other diseases. By removing these weeds, roots and all, you will have a healthier garden next year.

    Ripening tomatoes

    If you’ve brought in tomatoes from your garden to escape those killing frosts, pick ones that have shown a bit of color, since they will ripen more easily. To aid the process, put them in a closed container with a fully ripe apple or two. The apples naturally give off ethylene gas, which helps the tomatoes to ripen more quickly.

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    November tips

    Guy wires

    If you have newly-planted trees which are supported by guy wires, fall is a good time to check to make sure that the protective hose is still in place so that the tree won’t be damaged. Winter winds can whip trees around a lot, and if the protection isn’t in place, the wire could cause severe damage.

    Watering evergreens

    Even though the leaves may be falling from your deciduous trees, and they’ll soon be entering their dormant phase, don’t forget that your evergreens are still actively growing and need water. This is especially important if there are dry periods during fall or winter. Keep an eye on them and add water as needed, being sure not to over-water.

    Fall rose care

    During the fall it’s especially important to clean up your rose bed to remove disease organisms before the next growing season. Remove and destroy all fallen, diseased leaves. But don’t prune your roses just yet. Late winter or early spring is the preferred time, just before new growth begins.

    Fall soil Testing

    Fall is a good time to have your soil tested. If you need to adjust your pH, applying lime or sulfur now will give plenty of time for the soil to adjust to a balanced level. The soil test will tell you exactly how much to add. Bring a soil sample by any University of Missouri Extension center, and we’ll be happy to help you.

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    December tips

    Storing bulbs

    If you are storing bulbs inside over the winter you need to keep an eye on them from time to time. If you notice that they are beginning to shrivel, they are too dry. To remedy the situation, place them in a container with potting medium, peat moss, or even sawdust which is not-too-dry but not-too wet. That should stop the loss of water.

    Christmas tree water use

    Christmas trees can absorb from two pints up to a gallon of water per day, depending on the environment. Be sure to check the water level in the Christmas tree stand daily, and never let it run dry. If it does run dry, an air lock could form in the trunk, and that will keep the tree from absorbing water again, leading to a shortened tree life.

    Winter tree care

    Young trees are particularly susceptible to damage from mice chewing off the bark at or below ground level. If this completely girdles the tree, it will die. To help prevent this damage, keep mulch pulled away from the trunk at least a foot. This will discourage them from nesting there. If rabbits are a problem, you may need to wrap the trunk with a plastic tree wrap to minimize damage.

    House plant fertilization

    House plants do need a little fertilizer from time to time, but remember not to overdo it. During the winter, with lessened light levels, they will not be as active as when you had them outdoors on the patio last summer. Reduced activity means less nutrient need, and they may not need any fertilizer until spring.

    Citrus seeds

    Looking for an interesting house plant to try this winter? Take seeds from fresh grapefruits or oranges and sow them in a well-drained sandy soil. They’ll soon produce attractive plants. Of course, they will eventually outgrow the space available to them, but in the mean time you’ve been able to enjoy a unique green plant which has brightened up your home.