Horticulture 2021 Newsletter No. 36

KSRE - Horticulture News


Blog Post: http://www.ksuhortnewsletter.org

Video of the Week: Cuttings to Grow Inside for the Winter

Kansas Forest Service Tree, Shrub Seedling Sale, September 1 – October 15

• Fertilize cool-season lawn (Kentucky bluegrass or tall fescue) if haven’t done so yet.
• Dig gladiolus when foliage begins to yellow and air dry before storing.
• Buy spring-flowering bulbs while selection is good. Plant in late September through October

Lawn Seeding Best Done in September
September is the best month to reseed cool-season lawns such as tall fescue and Kentucky bluegrass. See last week’s newsletter for information on how to seed or overseed. We usually recommend not planting Kentucky bluegrass past early October. However, you can get by with an early to mid-October planting for tall fescue. October 15 is generally considered the last day for safely planting or overseeding a tall fescue lawn in the fall. If you do attempt a late seeding, take special care not to allow plants to dry out. Anything that slows growth will make it less likely that plants will mature enough to survive the winter.

Seedings done after the cut-off date can be successful, but the success rate goes down the later the planting date. Late plantings that fail are usually not killed by cold temperatures but rather desiccation. The freezing and thawing of soils heave poorly rooted grass plants out of the ground, which then dry and die. Keeping plants watered will help maximize root growth before freezing weather arrives. (Ward Upham)

Harvesting Sweet Potatoes
Sweet potatoes should be harvested no later than the first fall freeze because cold temperatures can damage the sensitive roots. However, you may want to harvest earlier than normal. Test dig a hill to see if they are the size you want.

Sweet potatoes should be cured after being dug. The digging process often damages the tender skin, and curing helps these small wounds heal. Place the roots in a warm, humid location for 5 to 10 days immediately after digging. A location with a temperature around 85 to 90 degrees is ideal. A space heater can be used to heat a small room or other area. Raise the humidity by placing moist towels in the room. The curing process not only heals wounds but also helps convert starches to sugars. This process improves the texture and flavor of the roots.

Sweet potatoes should be stored above 55 degrees. Storage at temperatures below that injures the roots, shortens storage life and gives them an off flavor. (Ward Upham)

Rotation of Vegetable Crops
Rotating vegetable crops is a standard way of helping prevent disease from being carried over from one year to the next. Rotation means that crops are moved to different areas of the garden each year. Planting the same crop, or a related crop, in the same area each year can lead to a build-up of disease.

Also, different crops vary in the depth and density of the root system as well as extract different levels of nutrients. As a rule, cool-season crops such as cabbage, peas, lettuce and onions have relatively sparse, shallow root systems and warm-season crops such as tomatoes, peppers and melons have deeper, better developed root systems. Therefore, it can be helpful to rotate warm-season and cool-season crops.

As mentioned earlier, it is also a good idea to avoid planting closely related crops in the same area as diseases may be shared among them. For example, tomatoes, potatoes, peppers and eggplant are closely related. Also, broccoli, cauliflower, cabbage and brussels sprouts share many characteristics in common. For example, do not plant cabbage where broccoli was the previous year or tomatoes where the peppers were.

So, why is this important to bring this up in the fall? Now is the time to make a sketch of your garden so that the layout is not forgotten when it is time to plant next year. (Ward Upham)

How to Water Trees
We have a lot of areas of the state that have been dry or are becoming dry. Trees are often a challenge to water. Following are some ideas on possible methods.

Small trees: Make sure the surrounding soil is moistened as well as the root ball to encourage roots to move out of the root ball. Soil should be moistened but not waterlogged. Water the root ball and the surrounding soil to a depth of 12 inches. This can be done in a number of ways.

– Set hose close to tree and run at a slow trickle.
– Drill a small hole near the base of a 5 gallon plastic bucket. Fill the bucket with water so that the trickle of water from the hole slowly moistens the soil.
– Use a rubber soaker hose. I usually do not recommend these because they put out different rates of water along their length. If they are coiled around the tree several times, the rates even out.
– Use a Tree Gator. This is a plastic watering bag that is placed around the tree. The bag is filled with water and slowly trickles out to water the tree.
– Drip irrigation can be used if watering a line or grouping of trees or shrubs.
Larger trees: Large trees are more often more difficult to water because the root system covers a large area. Concentrate on the area under the dripline. Though roots extend much further out than this, the greatest concentration of roots is found under the dripline.
– Sprinklers can be used if lower limbs don’t interfere with the pattern.
– Set a hose at a trickle and move when needed.
– Soaker hoses can be used but remember that the application rate varies along the length of the hose. Use a Y-Adapter to hook both the beginning and end of the soaker hose to help even out the flow. You will need a female by female fitting to connect the Y-Adapter to the end of the soaker hose.

– Drip irrigation is my favorite method because you- can make one set and water the tree. Also, the rate of application is uniform. Start at the base of the tree and spiral out to the dripline. Try to keep the tubing within 18 to 24 inches of the last spiral to make sure the entire area has been covered.

There is no set amount for how much to water because soils and application rate vary far too much. Gardeners can easily calculate how much to water for their conditions. Record the time you started watering and check the depth the water reaches periodically. When the 12-inch depth is reached, note how many minutes (or hours) were required. The depth can be checked with a metal rod such as an electric fence post, a wooden dowel or a screwdriver with a long tang. From then on, you can water on the clock. You still may want to double check because the starting soil moisture level will vary. (Ward Upham)

Ornamental Sweet Potatoes
We often receive the question as to whether ornamental sweet potatoes are safe to eat. The answer is yes. Note that they are chosen for ornamental qualities rather than flavor and so may not have the quality nor the nice shape of our traditional types. See the accompanying article on how to cure them. (Ward Upham)

Garden Spiders
People may become concerned when they see a large, noticeable spider setting up shop in or near the garden. These garden spiders feed on insects and are considered beneficial.
There are actually two common species of garden spiders in Kansas that are active during the day. The yellow garden spider has a black abdomen with yellow to yellow-orange markings. The black legs have a yellow or reddish band.

The banded garden spider has numerous bands on both the abdomen and legs. Those on the abdomen are alternating white and dark bands. The legs have alternating black and orange bands. Both of these spiders are orb weavers that spin large webs with the typical spider web shape.

Though these garden spiders have poor eyesight, they are extremely sensitive to vibrations that pass through the web and use this sensitivity to capture their prey. Since these spiders are beneficial and harmless to humans, it is recommended that they be left alone. (Ward Upham)

Contributors: Ward Upham, Extension Associate

Division of Horticulture
1712 Claflin, 2021 Throckmorton
Manhattan, KS 66506
(785) 532-6173

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