Small Peaches

Late frosts that kill peach flowers are common in Kansas. Many areas will not have a full peach crop except for about one in every seven (or more) years. This year has been exceptional, with full fruit crops and excellent peach-growing weather in most areas. However, we have been receiving reports of trees with small peaches. Though small fruit could be due to poor weather (rare this year) or heavy fruit crops (common), there is a third possibility that is often overlooked. That possibility occurs when the top portion of the peach dies and the rootstock puts up new growth.

Peaches, like other fruit plants, must be vegetatively propagated. In other words, you cannot grow fruit from seed and expect the progeny to share the same characteristics as the parent. Therefore, good fruit trees have a top portion called the scion (the good fruiting part) and a bottom portion known as the rootstock. This combination is made by grafting or budding the scion onto the rootstock. Virtually everything above ground will be the scion and everything below ground will be the rootstock. The rootstock may keep the tree smaller, be more disease resistant than the scion, delay bloom or give some other good characteristic to the tree. However, the rootstock normally does not produce good, high quality fruit. Therefore, if the scion dies and the rootstock throws up new growth, the fruit produced will most likely be of poor quality.

So how do you tell if the small fruit is due to a rootstock taking over? If the fruit produced is always poor quality, then suspect the rootstock problem. If this is the case, there is no remedy. The tree will not produce good quality fruit regardless of the care given. It would be best to remove and replace the tree.

Articles reprinted from the K-State Research & Extension Horticulture Newsletter

Grub Damage on Lawns

If your lawn has large dead patches, check to be sure that the damage has not been caused by grubs. This is easily done by pulling up handfuls of dead turf. If the turf comes up like a carpet, then you have grubs. Treatments this late in the season are best done with trichlorfon (Dylox, Bayer 24-hr Grub Control). Products that contain imidacloprid (Bayer’s Season-Long Grub Control and Grub-Ex) and halofenozide (Kill-a-Grub) are better applied earlier in the season as grub preventers. It is important that this product be watered in immediately after application. Waiting as little as 24 hours can reduce effectiveness to the point that grubs are not controlled. Apply 1/4 inch of water to insure the insecticide reaches the grubs.

Articles reprinted from the K-State Research & Extension Horticulture Newsletter

Power Raking and Core-Aeration

September is the optimum time to power rake or core-aerate tall fescue and Kentucky bluegrass lawns. These grasses should be coming out of their summer doldrums and beginning to grow more vigorously. This is a good time to consider what we are trying to accomplish with these practices.

Power raking is primarily a thatch control operation. It can be excessively damaging to the turf if not done carefully. For lawns with one-half inch of thatch or less, I don’t recommend power raking. For those who are unsure what thatch is, it is a springy layer of light-brown organic matter that resembles peat moss and is located above the soil but below the grass foliage.

Core-aeration is a much better practice for most lawns. By removing cores of soil, core-aeration relieves compaction, hastens thatch decomposition, and improves water, nutrient, and oxygen movement into the soil profile. This operation should be performed when the soil is just moist enough so that it crumbles easily when worked between the fingers. Enough passes should be made so that the holes are spaced about 2 to 3 inches apart. Ideally, the holes should penetrate 2.5 to 3 inches deep. The cores can be left on the lawn to decompose naturally (a process that usually takes two or three weeks, depending on soil-type), or they can be broken up with a vertical mower set just low enough to nick the cores, and then dragged with a section of chain-link fence or a steel doormat. The intermingling of soil and thatch is beneficial to the lawn.

Articles reprinted from the K-State Research & Extension Horticulture Newsletter

Give Cool-Season Grasses a Boost

September is almost here and that means it is prime time to fertilize tall fescue or Kentucky bluegrass lawns. If you could only fertilize cool-season grasses once a year, this would be the best time to do it.

These grasses are entering their fall growth cycle as days shorten and temperatures moderate (especially at night). Cool-season grasses naturally thicken up in the fall by tillering (forming new shoots at the base of existing plants) and, for bluegrass, spreading by underground stems called rhizomes. Consequently, September is the most important time to fertilize these grasses. Apply 1 to 1.5 pounds of actual nitrogen per 1,000 square feet. The settings recommended on lawn fertilizer bags usually result in about 1 pound of nitrogen per 1,000 square feet. We recommend a quick-release source of nitrogen or a combination of quick- and slow-release nitrogen sources at this time. Most fertilizers sold in garden centers and department stores contain either quick-release nitrogen or a mixture of quick- and slow-release. Any of these should be fine to use at this time of year.

The second most important fertilization of cool-season grasses also occurs during the fall. A November fertilizer application will help the grass green up earlier next spring and provide the nutrients needed until summer. It should be quick-release applied at the rate of 1-pound actual nitrogen per 1,000 square feet.

Articles reprinted from the K-State Research & Extension Horticulture Newsletter

Fall Lawn Seeding Tips

The keys to successful lawn seeding are proper rates, even dispersal, good seed to soil contact and proper watering. Evenness is best achieved by carefully calibrating the seeder or by adjusting the seeder to a low setting and making several passes to ensure even distribution. Seeding a little on the heavy side with close overlapping is better than missing areas altogether, especially for the bunch-type tall fescue, which does not spread. Multiple seeder passes in opposite directions should help avoid this problem.

A more serious error in seeding is using the improper rate. For tall fescue, aim for 6 to 8 pounds of seed per 1,000 square feet for new areas and about half as much for overseeding or seeding areas in the shade. Using too much seed results in a lawn more prone to disease and damage from stress. The best way to avoid such a mistake is to determine the square footage of the yard first, and then calculate the amount of seed. Using too little seed can also be detrimental and result in clumpy turf that is not as visually pleasing.

Establishing good seed to soil contact is essential for good germination rates. Slit seeders achieve good contact at the time of seeding by dropping seed directly behind the blade that slices a furrow into the soil. Packing wheels then follow to close the furrow. The same result can be accomplished by using a verticut before broadcasting the seed, and then verticutting a second time.

Core aerators can also be used to seed grass. Go over an area at least three times in different directions, and then broadcast the seed. Germination will occur in the aeration holes. Because those holes stay moister than a traditional seedbed, this method requires less watering. If seeding worked soil, use light hand raking to mix the seed into the soil. A leaf rake often works better than a garden rake because it mixes seed more shallowly.

Water newly planted areas lightly, but often. Keep soil constantly moist but not waterlogged. During hot days, a new lawn may need to be watered three times a day. If watered less, germination will be slowed. Cool, calm days may require watering only every couple of days. As the grass plants come up, gradually decrease watering to once a week if there is no rain. Let the plants tell you when to water. If you can push the blades down and they don’t spring back up quickly, the lawn needs water.

Once seed sprouts, try to minimize how much traffic (foot, mower, dog, etc.) seeded areas receive until the seedlings are a little more robust and ready to be mowed. Begin mowing once seedlings reach 3 to 4 inches tall.

Articles reprinted from the K-State Research & Extension Horticulture Newsletter

Is My Lawn Still Alive?

Many lawns have gone dormant recently due to hot conditions and a lack of moisture. Homeowners often wonder if dormant grass is still alive. Healthy lawns can go dormant for 5 to 8 weeks without harm and so most lawns should be fine. However, to be sure, pull up an individual plant and separate the leaves from the crown. The crown resembles a grain of rice and is the area between the leaves and the roots. If it is still hard and not papery and dry, the plant is still alive.

If you wish to pull the lawn out of dormancy, water to a depth of 6 to 8 inches each week. The lawn will begin to grow and eventually green up. However, it is better to let a lawn remain dormant than to water enough to pull it out of dormancy and then allow it to go dormant again. Stored energy reserves are used each time to plant has to come out of dormancy and eventually the plant will deplete these reserves and die.

Articles reprinted from the K-State Research & Extension Horticulture Newsletter

How Much to Water a Lawn

We have received several questions on how much to water a lawn. Homeowners usually want to know how much and how long to leave the sprinklers on. There are too many variables to give a solid answer. You will need to do some experimentation to determine what is needed for your lawn.

The key is to make sure water reaches about 8 inches deep. This can be checked with a wooden dowel or a metal rod (rebar or electric fence post). Pushing it into the soil will tell you how deeply water has reached as it will stop when it hits dry soil.

Start by placing a tuna can or something similar in the lawn to see how much water is applied. Then water for 15 minutes and check the depth of watering. If the soil is only moist 4 inches deep, then you will need to water another 15 minutes. Check again after the second watering to be sure moisture reaches your desired depth. Watch for runoff. If you see any before the soil is wet to the desired depth, you may have to run two cycles back to back to allow time for the water to soak in from the first cycle before adding additional water for the second cycle. If there is still runoff before water reaches the desired depth, more waterings per week may be needed to make up for the shallow depth the water is reaching. On such lawns, core aeration during September would be highly recommended to help increase the rate at which the soil absorbs water.

That brings up how often should we water. During most of the growing season, once per week will be adequate. However, during extreme heat or on heavy soils where runoff occurs quickly, twice a week may be needed.

Articles reprinted from the K-State Research & Extension Horticulture Newsletter

Pear Harvest

Pears should not be allowed to ripen on the tree. They should be picked while still firm and ripened after harvest. Tree-ripened fruits are of poor quality because of the development of grit cells and the browning and softening of the inner flesh. Commercial growers determine the best time to harvest pears by measuring the decrease in fruit firmness as the fruit matures. This varies with growing conditions and variety. A Magness meter is used for testing and measures the pressure needed to push a 5/16-inch tip a specified distance into an individual fruit. Home gardeners can use these other indicators:

1. A change in the fruit ground color from a dark green to light green or yellowish green. The ground color is the “background” color of the fruit.

2. Fruit should part easily from the branch when it is lifted up and twisted.

3. Corking over of lenticels. Lenticels are the “breathing pores” of the fruit. They start out as a white to greenish white color and turn brown due to corking as the fruit nears maturity.

4. Development of characteristic pear aroma and taste of sampled fruit.

Pears ripen in one to three weeks after harvest if held at 60 to 65 degrees F. They can then be canned or preserved. If you wish to store some for ripening later, fresh-picked fruit should be placed in cold storage at 29 to 31degrees F and 90 percent humidity. Ripen small amounts as needed by moving them to a warmer location and holding them at 60 to 65 degrees F. Storing at too high a temperature (75 degrees F and higher) will result in the fruit breaking down without ripening.

Articles reprinted from the K-State Research & Extension Horticulture Newsletter

Fertilize Strawberries mid-August

An August application of nitrogen on spring-bearing strawberries is important in order to increase the number of strawberries produced next spring. Plenty of daylight and warm temperatures during June, July and August promote the growth of new runner, or daughter, plants. As daylight hours dwindle and temperatures grow cooler in September and October, fruit buds for the next year’s fruit crop develop. To get a good berry crop next spring, it is important for strawberry plants to be vigorous during this period of fruit bud development. Nitrogen, applied mid-August, will help promote fruit bud development. A general application rate is ½ to 3/4 pound of actual nitrogen per 100 feet of row. The nitrogen may be in the form of a fertilizer mixture such as 12-12-12, or in a fertilizer containing only nitrogen such as urea (46-0-0) or ammonium nitrate (33-0-0). Some specific examples would include: Iron + (11-0-0) at 6 pounds per 100 feet of row 12-12-12 at 5.5 pounds per 100 feet of row Nitrate of soda (16-0-0) at 4 pounds per 100 feet of row Ammonium sulfate (21-0-0) at 3 pounds per 100 feet of row Urea (46-0-0) at 1.5 pounds per 100 feet of row

On sandy soils, the rate may be increased by about a half. After spreading the fertilizer, apply at least a half-inch of water to move the nitrogen into the strawberry root areas.

Articles reprinted from the K-State Research & Extension Horticulture Newsletter