Horticulture 2014 Newsletter No. 14 April 8, 2014 VEGETABLES

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1 Horticulture 2014 Newsletter No. 14 April 8, 2014 Video of the Week: Crabgrass Prevention in Lawns Blanching Cauliflower VEGETABLES Gardeners that haven t grown cauliflower before are often surprised that the heads of most varieties are a yellowish color and not the white they expect. The yellowish color is a reaction to sunlight. In order to have the heads remain white, the developing heads must be covered to protect them from the sun. This is commonly done by pulling several of the outer leaves over the head when the head is the size of a silver dollar. Hold the leaves in place by a clothespin, rubber band, tape or soft twine. Plants need to be checked every few days to make sure the curds of the expanding head don t begin to show. There are some varieties that are self-blanching but watch them to make sure the leaves actually do cover the head. Self-blanching varieties are more likely to work in cool weather. (Ward Upham) Starting Tomatoes Early If you would like to have your tomato plants produce earlier in the year, there are certain things to keep in mind. Most people who try to get a jump on the season set their tomatoes out early and hope they do well. However, that is often not a good plan, as tomatoes have to have certain requirements before they will grow well. Those requirements are an acceptable soil temperature for root growth and an acceptable air temperature for both plant growth and fruit set. Root Growth: Tomatoes need a soil temperature of at least 55 degrees to do well. Plastic mulch

2 is most commonly used to warm the soil. Several days may be needed to raise the soil temperature. Check the soil temperature 2.5 inches deep in the soil at about 11:00 a.m. You may wish to lay a drip irrigation line before installing the plastic to make watering more convenient. See accompanying article on laying plastic mulch. Air Temperature: Plants must be protected from frost. Hot caps or water teepees are placed over the young plants to provide protection as well as a higher average temperature to encourage growth. Eventually the plants will outgrow the cover and start to develop flowers. But if the temperature goes below 55 degrees at night, tomato flowers may not set. The plant is not hurt, but the blossom will not set fruit or, if it does set fruit, the fruit is often misshapen. How early can you transplant? Start with a date about 2 weeks earlier than normal. (Ward Upham) Setting Up Water Teepees If you use water teepees to get your tomatoes off to an early start, you have probably struggled with their tendency to fall over as you try to fill them. An old trick is to use a 5-gallon plastic bucket to make the process easier. The bucket works much better if it is modified by taking the handle off and drilling a hole (use a hole saw bit) in the bottom of the bucket. Place the bucket upside down over the plant you wish to protect and place the water teepee over the bucket. Now the bucket will support the teepee as it is filled. Once the teepee is filled, the bucket can be removed by sticking your finger into the hole and pulling straight up. You may also want to support the teepee after it is filled by using a metal rod (rebar or an electric fence post) on the inside of the teepee. The metal rod is pushed into the soil to keep the teepee from collapsing from high winds. (Ward Upham) Controlling Weeds in Strawberries FRUIT Controlling Weeds in Strawberries Strawberries are one of the most popular fruits, but gardeners often have problems with weed control. Strawberries form a mat of plants, which makes hoeing difficult. Gardeners must pull weeds by hand or use herbicides. Although there are no weed preventers available for homeowners to use on strawberries, Poast (sethoxydim), a grass-killing herbicide, can be used after weedy grasses have emerged. It can be sprayed directly over strawberries without harm but should not be applied within 7 days of harvest. You can find Poast in Fertilome Over the Top II, Hi-Yield Grass Killer and Monterey Grass Getter. (Ward Upham)

3 TURFGRASS Keep Mower Blades Sharp Lawn-mowing season is here. Remember that dull blades give the lawn a whitish cast. A dull blade does not cut cleanly but rather shreds the ends of the leaf blades. The shredded ends dry out, giving the lawn that whitish look. A sharp mower blade is even more important when the turf starts putting up seed heads in a month or so. The seed head stems are much tougher than the grass blades and more likely to shred. Under normal use, mower blades should be sharpened about every 10 hours of use. (Ward Upham) ORNAMENTALS Top 10 Spring Flowering Shrubs Our world is finally greening up just a bit. Isn t it refreshing? Some of the first plants to peek out of the ground are spring-flowering bulbs like crocus, daffodil, and tulip. It s fun to keep your eye out for the tips of their leaves poking out of the ground; however, we ll chat about those plants in a future article. For now, let s talk about some beautiful spring-flowering shrubs we ll be seeing very soon, if not already. So, without further ado, I give you a top 10 list of spring-flowering shrubs (in order of flower appearance). Witchhazel (Hamamelis x intermedia) Perhaps even earlier-flowering than forsythia, is Arnold Promise witchhazel. This shrub can flower starting in late January (unless we have unusually cold winter weather like polar vortices) and keep going all the way into March (sometimes April!). Bright flowers are yellow with red tinges, though there are red-flowering cultivars available. Witchhazel can be grown as a shrub or a small tree and offers some yellow/orange/red fall color. Forsythia (Forsythia x intermedia) Forsythia is the traditional first-flowering plant in the spring. Tough as nails, their bright yellow blooms can catch your eye anywhere (from a garden to an abandoned homestead). Many great new cultivars are on the market, but it s important to remember that this is a one season plant that provides little interest the rest of the year. Quince (Chaenomeles speciosa)

4 Another one of the earliest flowering shrubs is quince. In early April you ll find these shrubs covered with flowers that are 1.5 to 1.75 inches wide (each). There are several cultivars and you may see white-flowering plants ( Jet Trails ), red-flowering plants ( Texas Scarlet ) or even large, double, fluffy, peach-pink flowers ( Cameo ). After the show, this plant tends to fade into the background, though I ve noticed that birds enjoy sheltering in its branches. Koreanspice Viburnum (Viburnum carlesii) One of my very favorites! Notice that this is not a list of the top 10 fragrant spring-flowering plants, but if it were, this would be at the top of the list. Well, maybe tied for first with lilac, but I digress. Koreanspice viburnum blooms in late April with blooms that are pink/red while they are still in buds, opening to white flowers that are each a half inch wide. The flowers are presented on dense 2-3 inch groupings called cymes (semi-snowball) and the fragrance, well the fragrance can float up 2-3 stories high and pull you off the sidewalk to find it. Even dried flowers can retain the fragrance for at least 2 years. And luck of all luck, they have nice, clean leaves in the summer and great fall color. Can t beat that in a multi-season shrub. Flowering Almond (Prunus glandulosa) Here s a plant with one season of interest, though it s a doozy. Flowering almond, particularly the cultivar Rosea Plena has tons of pink flowers (double lots of petals). Some cultivars have white flowers, and all present in late April or early May. Another small plant, it grows well in full sun, but is not interesting the rest of the year. Shadblow Serviceberry (Amelanchier canadensis) A multi-season-interest plant, serviceberry offers white flowers on 2-3 inch long inflorescences in April, which leads to sweet, juicy black fruit in the summer. Some plants can also have decent fall color (yellow with hints of orange and red). Serviceberry grows by suckering so it s perhaps not a great choice for a small yard. Lilac (Syringa vulgaris) Tied for first in the fragrant spring-flowering plants list is the well-deserved lilac. The beautiful purple flowers (many, many colors are available, but purple is most common) are wonderfully fragrant in late May. They may only bloom for 2 weeks, but man are those 2 weeks worth having a lilac in your garden! Takes me straight back to my childhood. Now, unlike the Koreanspice viburnum, lilac doesn't have much to offer for interest in other seasons. It s a good one to have in the back of your garden where it can shine in May and then fade into the background the rest of the year. Black Chokeberry (Aronia melanocarpa) An adaptable species, this plant is known for long-lasting black fruit in the fall and wine-red fall color. Spring flowers are white, presented in groups of 9-20 resulting in 1 to 1.5 inch groupings covering the plant in May. This species can spread and colonize large areas, which makes for a striking mass effect in the spring. Small plant (under 5 feet) thrives in part shade to full sun. Mockorange (Philadelphus coronarius)

5 Fans of mockorange are serious about their use in the landscape. These plants can take care of themselves and they ll reward you every May/June with white, fragrant flowers that are 1 to 1.5 inches wide. Another one season plant. Siberian Peashrub (Caragana arborescens) Granted, this is a great shrub for harsh sites (poor soils, drought, alkaline soil, cold, wind), but it s unusual and doesn't take much care. Leaves are pea-green and emerge with the yellow flowers in May. Later in the summer the fruit of the flowers, a narrow pod, makes a popping sound when it opens. Bonus feature: it fixes atmospheric nitrogen. Remember, plants with more than one season of interest are like hitting the landscape jackpot. So, if you ve chosen one of these plants because you love the flowers in the spring, just be aware that it may need to fade into the background for the rest of the year. Having said that, plants that usher in the new season are anticipated, loved and enjoyed. Make sure you ve got some of these I n your neighborhood for a dose of early spring joy. (Cheryl Boyer) Laying Plastic Mulch MISCELLANEOUS Plastic mulch is sometimes used to start vegetables such as tomatoes and melons earlier than normal. Commercial growers use a machine to lay the mulch, but home gardeners must do this by hand. Following are some tips on how this is done. 1. Fertilize according to soil test. You won't be able to add fertilizer after the plastic is down. 2. Work the soil so that the bed can be easily shaped. 3. Use a garden hoe to form a trench along all edges of the plastic. The soil should be pulled to the outside of the bed. The trench should be formed six inches in from the edge of the plastic and extend along both sides and both ends. The trench should be deep and wide enough to bury six inches of plastic. 4. Lay trickle irrigation tube down the center of the bed. This isn't absolutely necessary but it makes it much easier to water. Overhead watering will hit the plastic and roll off. 5. Lay the plastic down and cover the edges with soil. You may need to slit the edge of the plastic where the trickle irrigation tube enters the end of the bed. 6. Plant when the soil temperature reaches the correct temperature for the crop (55 degrees for tomatoes and 60 degrees for melons) at a 2.5-inch depth. Check the temperature at about 11:00

6 a.m. to get a good average temperature. Check for several days in a row to ensure the temperature is stable. (Ward Upham) Use a String Line and Planting Board Two simple tools can make planting a vegetable garden easier. A string line is used to insure straight rows and a planting board can make spacing vegetables within a row easier. Most gardeners make their own string line. A very simple one can be made with a tent peg, a 12" piece of 1 x 2 lumber and some string. String is wound on the 1 x 2. Either notch each end of the board or drive a nail near each end to hold the string as it is wound. The end of the string is tied to the nail driven into the board. The other end of the string is tied to the tent peg. When marking out a row, drive the tent peg into the ground where you want the row to start. Mark the end of the row with a second tent peg and unwind enough string to stretch between them. Actually you will want the string line offset where the plants will go by a couple of inches so that it isn t in your way. In other words, you will make your row next to the string; not under it. You now have the means of making a straight row. So what is a planting board? A planting board is a 1 x 4 board that is four feet long. Relatively deep notches are cut every foot with shallow notches at 6 inches from each deep notch. Some gardeners also bevel the side opposite the notches so they can work the beveled end into the soil to make a shallow trench for seed. When planting, lay the planting board near your tent peg and align it with the string. It is now easy to place plants or seeds at the recommended spacing. Move the planting board with you as you progress down the row. (Ward Upham) Contributors: Cheryl Boyer, Extension Nursery Crop Specialist; Ward Upham, Extension Associate To view Upcoming Events: The web version includes color images that illustrate subjects discussed. To subscribe to this newsletter electronically, send an message to cdipman@ksu.edu or wupham@ksu.edu listing your address in the message. For questions or further information contact: wupham@ksu.edu Brand names appearing in this publication are for product identification purposes only. No endorsement is intended, nor is criticism implied of similar products not mentioned.

7 Kansas State University Agricultural Experiment Station and Cooperative Extension Service