Blog Posts - K-State Horticulture Newsletter

Fertilizing Grapes

4/5/2021

Year of Planting: Apply one-half cup of a 10-10-10, 12-12-12 or similar fertilizer per vine as growth begins in the spring. Repeat after one month. Fertilizers should be spread evenly from the trunk out 3 to 5 feet.

Second Year: Apply 1 cup of a 10-10-10, 12-12-12 or similar fertilizer per vine as growth begins in the spring. Fertilizers should be spread evenly from the trunk out 3 to 5 feet.

Mature Vines (3 years and older): If the soil test recommends phosphorus and potassium, use a 10-10-10, 12-12-12 or similar fertilizer at the rate of 2 cups per mature vine. Fertilizers should be spread evenly from the trunk out 3 to 5 feet.

If, however, there are adequate levels of phosphorus and potassium, add 3/4 cup of a high nitrogen fertilizer such as a 27-3-3, 29-5-4, 30-3-3 or something similar instead of the 10-10-10. Though recommended for lawns, these fertilizers will also work well as long as they do not contain weed killers or crabgrass preventers. Fertilizers should be spread evenly from the trunk out 3 to 5 feet. (Ward Upham)

Fertilizing the Home Orchard

4/5/2021

Fruit trees benefit from fertilization around the bloom period, but the amount needed varies with the age of the tree. Normally, trees primarily need nitrogen, so the recommendations are for a high nitrogen fertilizer such as a 27-3-3, 29-5-4, 30-3-3 or something similar. Though recommended for lawns, these fertilizers will also work well as long as they do not contain weed killers or crabgrass preventers. Use the following rates:

Trees 1 to 2 years old, apply one-fourth cup of fertilizer per tree;
Trees 3 to 4 years old, apply one-half cup per tree;
Trees 5 to 10 years old, apply 1 to 2 cups per tree;
Trees more than 10 years old, apply 2 to 3 cups.

You may also use nitrate of soda (16-0-0) but double the rate recommended above. If a soil test calls for phosphorus and potassium, use a 10-10-10 but triple the rate.

On apple trees, last year's growth should be 8 to 10 inches, cherries should have 10 to 12 inches, and peaches should equal 12 to 15 inches of terminal growth. If less than this, apply the higher rate of fertilizer, and if more, apply the lesser amount.

Spread all fertilizer evenly on the ground away from the trunk of the tree and to the outer spread of the branches. Water in the fertilizer with at least 1/4 inch of water if rain does not do the job for you. (Ward Upham)

Blanching Cauliflower

4/5/2021

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 hue 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 with a 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)

There Never Used to be Fruit on Ornamental Pears

4/5/2021

The fruit on ornamental pears is quite small; about the size of a marble. However, it can be very messy if it lands on sidewalks or driveways and people squish the fruit when walking or driving. You may have noticed that ornamental pears are producing fruit much more commonly than they have in the past. Why is this so? A little history is needed in order to understand what has happened.

Ornamental pears used to be called Bradford pears. This was a bit of a misnomer as ‘Bradford’ was a specific variety. Ornamental pears were called Bradfords because this was practically the only variety that people planted. Therefore, if you bought an ornamental pear a number of years ago, it was likely a Bradford. All was well and good until people noticed that Bradfords would fall apart after a number of years due to a weak branching structure. Therefore, nurseries started selling “improved” ornamental pears that were not Bradfords such as ‘Aristocrat’, ‘Capital’, ‘Redspire’, ‘Chanticleer’ and various other varieties. It was felt that all of these varieties had a stronger branching pattern that ‘Bradford’ but such may not be the case. Both ‘Chanticleer’ and ‘Redspire’ have shown branch breakage. ‘Aristocrat’ does appear to have better branch angles but more time is needed to make a firm recommendation.

Here is the key. Pears usually require cross-pollination in order to fruit. In other words, you must have two different varieties of pear before fruit forms. When all we had were Bradfords, we had no fruit due to a lack of cross-pollination. Now that we have such a mixture of varieties, we will get fruit as long as two different varieties of ornamental pears bloom at the same time and are close enough that bees can work between them.

This formation of fruit can also lead to a second problem. Volunteer trees can come up from the seed contained in the fruit. Therefore, you may see ornamental pears come up in areas where no one planted them. This has become enough of a problem that several states have added ornamental pears to their invasive plant list.

There are products that are sold as fruit preventers such as Florel but timing and air temperature are critical and our results have been mixed. (Ward Upham)

Planting Easter Lilies Outside

4/5/2021

Gardeners often hate to throw out Easter Lilies after they finish blooming and may wonder if they can grow outside. Though not reliably hardy in Kansas, many gardeners have success if they follow a few simple rules.

1. After the flowers have faded, remove the flower stalk so that energy does not go into making seed.

2. Keep the plant inside until the danger of frost is past. Keep soil moist but never waterlogged. Don’t allow water to sit in the tray. Continue to fertilize.

3. The pot can be moved outside when frost is no longer a concern. Sinking the pot into the soil up to the brim and placing in dappled shade will help reduce watering. Continue to water and fertilize until the top growth dies down.

4. Choose a sunny, well-drained spot for planting. Good drainage is vital for lilies and so the addition of organic matter is usually necessary for most soils. Till or dig the soil 6 inches deep and add 3 inches of peat moss. Mix the soil and peat moss together. This will form a berm that should drain very well.

5. Plant the bulbs 6 inches deep and 12 to 18 inches apart and water in well. Mulch to conserve moisture. New growth may appear later in the summer or the plant may stay dormant until the following spring.

6. Cover the plants in the fall after the foliage has died down with straw, pine needles, wood chips or other types of mulch to help protect the plant over winter. Use 4 inches of straw or 3 inches of any of the other materials.

7. Uncover the plants in the spring to allow new growth to appear and fertilize according to soil test. (Ward Upham)

Controlling Grassy Weeds in Broadleaf Plants

4/5/2021

Most gardeners are familiar with herbicides that can be used to eliminate broadleaves from grasses (i.e. dandelions from lawns). However, gardeners may not be as familiar with herbicides that can take grasses out of broadleaf plants like shrubs. There are two major weed killer types labeled for homeowners that are used to kill grassy weeds in broadleaf plants. On the commercial side, the trade names for these products are Fusilade and Poast. Homeowner labeling is more diverse. I have seen Fusilade sold under the names of Ortho "Grass-B-Gon”. Poast is sometimes sold to homeowners under the Poast label but I've seen it more commonly sold as “Bonide Grass Beater”, “Fertilome Over the Top II Grass Killer", "Hi-Yield Grass Killer" and "Monterey Grass Getter." There may be other trade names, too. Fortunately, you can identify the product by the common chemical name listed on the label. Fusilade's common chemical name is fluazifop, and Poast's is sethoxydim.
If you decide to use one of these products, read the label carefully. Often, a crop oil must be added to the spray solution for the herbicide to work well. Some grassy weeds are not controlled such as bromegrass and sandbur. Mature tall fescue also is not controlled though seedling tall fescue is. Established bermudagrass is knocked back but rarely killed.
Though both these products can be used over the top of numerous broadleaf plants (including iris), there are some differences in labeling. For example, if you need to control grasses in vegetables, choose Poast as Fusilade is not labeled for vegetables. However, Poast products cannot be used on all vegetables and the waiting period between spraying and harvest may be so long as to make use impractical. To see a label for one of the products that contain sethoxydim, see Hi-Yield Grass Killer. (Ward Upham)

Lawnmower Maintenance

3/29/2021

Growing Vegetables Vertically

3/29/2021

If you wish to make more efficient use of the space in your garden, consider growing some of your crops vertically. Growing vertically not only helps conserve space but can also help prevent disease due to better air movement. Also, harvesting can be easier.

Most people are familiar with tomato cages but other crops can also be trained to grow up a structure. Crops that can be grown vertically include pole beans, peas, and the vining crops such as cucumbers, melons, squash and gourds. Edible-pod and snow peas are better adapted to growing vertically than English (shelling) peas as they have longer vines. Also, avoid growing “bush-type” vining crops vertically as they are bred to produce short vines. Another thing to keep in mind is that large fruit from vining crops may need to be supported so they don’t damage the vine.

So what can be used as a structure? Bamboo poles are often used to form a teepee to support pole beans. Supports can also be made from cattle panels. These are often 16 feet long and may need to be cut in half for better fit. These two half-panels can then be tied to together at the top to form a “pup tent.” Crops can then be planted at the base of each panel. Another way to support a cattle panel is to tie the panel to T-posts so that it will stand upright. If you have a small garden, growing vertically can allow more crops to be grown. (Ward Upham)

Transplanting Tomatoes Early

3/29/2021

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 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. If that is not possible, check the temperature before leaving for work and again when you return and use the average of the two. It is best 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 provide 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)

How Low Should You Go

3/29/2021

We often are asked whether it is good to mow lower in the spring. The answer is yes and no. It doesn’t hurt to mow lower than normal the first mowing or two. As a matter of fact, it can actually speed green-up by removing old, dead grass and allowing the soil to warm up more quickly. But the mowing height should be raised to normal after the first or second cutting to discourage crabgrass and encourage deep rooting.

Crabgrass seed must have light to germinate and a high mowing height will help shade the soil. Also, root depth and mowing height are related on upright growing grasses such as tall fescue and Kentucky bluegrass — the higher the height of cut, the deeper the root system. A deeper root system means a more drought-resistant turf.

So, how low should you go on the first cutting? On tall fescue and Kentucky bluegrass, you can mow as low as 1 to 1½ inches. Be careful you don't go so low that you scalp the turf. After that, raise the mowing height for Kentucky bluegrass to 2 to 3 inches but 3 to 3½ inches for tall fescue. (Ward Upham)