Extension Educator, Local Food Systems and Small Farms
Extension Educator, Horticulture
March 24, 2010
Gardening time is also upon us. With a year like this one, it seems to really have snuck up on us. We went from really cold to above average with the flip of a switch. Anyway, when soil is fit, March 25 to April 10 is the normal seeding/planting time for asparagus crowns, cabbage seed, kohlrabi, leaf lettuce, onions from seeds or sets, peas, potatoes, radish, rhubarb plants, spinach, and turnips.
March 24, 2010
Advancing trees and shrubs brings to mind the sweet gum tree. This beautiful tree has been cursed with a fruit few care to see. Anyway, the most common control is ethephon, and it is used as a foliar spray to reduce or eliminate undesirable fruit or seeds. Some of the trade names include Florel and Ethrel. The product is effective at eliminating much of the fruit without affecting leaf growth and color, and it does not harm other plants that get some spray drift on them. It also does not affect the actual flowering of the treated trees. With ethephon, the key is in the timing. The application must be made during flowering, but before the fruit set in. For most flowering trees there is a 10-14 day window of opportunity. Sweet gums are a little tricky since there are no showy flowers involved, so effective sprays should occur just as new leaves begin to emerge. Sprays should leave leaves wet, but not to the point of dripping. Good coverage of the tree is needed, so keep in mind the size of the tree when you are weighing this option. If you can just spray the bottom half of the tree, the top of the tree will still be loaded with sweet gum balls come next fall and winter.
March 24, 2010
Another warm weather phenomenon is the advancing of the trees and shrubs. Pruning times have pretty well slipped by us for dormant pruning. The next group of shrubs to prune will be the flowering group after they get done flowering. This timing helps maximize the blooms the following year. Forsythia is an indicator for crabgrass germination, so it is about time to get preventative treatments on. Remember, if you are putting down new seed this spring, no crabgrass treatments should be applied. If you aren't controlling crabgrass, it is time to finish up new seedings and the intrusive operations such as dethatching and core aeration.
March 24, 2010
The warm weather has brought about many interesting things, both inside and outside the house. Inside the house, we have the Asian ladybugs to deal with. We also have them outside, but that is less of a concern. As we begin to clean up flower beds, or piled leaves around the house, we will disturb resting places of the ladybugs. This will cause them to seek a new place, and if it is warm and sunny enough, they may just create a little bit of a nuisance outside. Inside, we have a population coming out of hibernation. They have been there all winter, but have been under or behind things so you didn't know they were there. The best control around the house seems to be a cup of coffee or a glass of water for them to fly into. Seriously, sucking them up with a vacuum, or spraying areas with an aerosol flying insect killer is about as good as you can do.
Another insect becoming active with the warm weather is the ant. We are seeing winged ants being brought into the office on a regular basis. Ants become winged when they are overcrowded in their old colony, and are seeking to start a new one. Many are concerned about the identification of these winged insects to make sure they aren't termites. The process is relatively simple. Just look at the last body segment, and if it has a "pinched" waist, it is an ant. Termites don't have that hourglass figure, but are shaped more like a cigar. Of course you may bring samples by the office for identification. The office is located at 980 N. Postville Dr. in Lincoln (the NW corner of the fairgrounds off of the frontage road). Our phone number is 732-8289.
March 19, 2010
There are quite a few things that can be done shortly. You need to finish up pruning chores in short order for deciduous trees and shrubs. Remember that most of the flowers and fruit come on two year old wood. Trees with high sap flow rates will tend to leak a lot of sap when pruned this time of year. Another item is to watch roses to determine when to start uncovering and pruning. Many recommend doing your pruning chores when forsythia is in bloom. Also, if you haven't uncovered strawberries, keep an eye on them. They should be uncovered when you see green leaves under the straw, and definitely when you see yellow material – that means you are just a little late. Keep the straw handy in case you need to re-cover them. Thanks Dan for the reminder on the berries!
March 19, 2010
Warmer temperatures have us thinking spring. Lawns are greening up very quickly. Spring seeding lawns is usually our second best choice, because of the warm weather soon to follow, but last year it worked like a gem with the cool, wet weather. Fall has been the preferred time for many years, but once again, temperature and moisture have a great effect on success.
Spring seeding should be done between March 15 and April 1 for the best chance of success. The reasons for the early date are the heat and the long germination time for Kentucky bluegrass. It can take up to a month for bluegrass seed to germinate. This means an April 1 seeding might germinate May 1. Then add six to eight weeks for it to become established. This could then be close to July 1. Usually we tend to get hot weather by then. Let's start with the basics. The normal seedings are a blend of Kentucky bluegrass, perennial ryegrass, and fine fescue. The fine fescue is much better in shade, and the perennial ryegrass will provide quicker cover. The seeding rate is generally four pounds per 1000 square feet in bare dirt seedings. Use two pounds per 1000 square feet in overseeding thin lawns. Of course this can run into some real money when doing very large areas. Many rural seedings are done more on the basis of a pound per 1000 square feet. There are almost 44,000 square feet in an acre, so you can do the math on this one.
Fertilizer is always an area of many questions. The place to start is a soil test. This will tell you where you are starting from. Basic soil test levels for phosphorus, potassium, and soil pH should be in the neighborhood of 40, 350, and 6.1 respectfully. Phosphorus and potassium are on a pound per acre basis. This must be considered if you use labs that report in parts per million, which will give numbers half as large. These numbers will provide a great environment for grass. Grass will really grow in very poor conditions, but it certainly won't have that manicured lawn look many strive for. Lacking a soil test, or being at recommended fertility levels, general maintenance applications provide a pound each of nitrogen, phosphorus, and potassium per 1000 square feet of lawn area in May and again in September. Really lush lawns will usually have twice as much nitrogen applied in a season, but split among four applications. Hang on to your wallet again this year, as fertilizer prices have increased dramatically.
If you decide to try seeding this spring, remember a couple of things related to weed killers. Number one, you can't use crabgrass preventer in the same season as you put down seed. The crabgrass preventer doesn't know the difference between grass seed and weed seeds. The second rule is to mow the new seeding at least three times before trying any broadleaf weed killer. Generally this means spring broadleaf control doesn't happen when you seed in the spring. The end result is if you seed in the spring, you control weeds in the fall. Seed in the fall, and you control weeds and crabgrass in the spring. If you do plan to use a crabgrass preventer, time it so it is on about the time the forsythia blooms. This would be the approximate soil and air temperature needed for the crabgrass to germinate. April 1 is a good guess, but this date can vary widely with the weather. Many crabgrass preventers also only last for four to eight weeks, so plan on repeating the application in June anyway.
March 10, 2010
The infamous "to do" list can cause consternation, confrontation, and confusion. Hopefully a few reminders every now and then will help you avoid the 3-c problems.
March 10, 2010
This is one of "pull it out of the file and run it again" columns. Of course, in most cases, good management last year is good management this year for horticultural topics.
When it comes to spray programs for apple and pear trees, the two rules are to be consistent and be persistent. Quality fruit these days takes these two things, and time. It seems like quality fruit must be sprayed at the recommended intervals. Starting with dormant oils, these need to be applied before buds swell. Dormant oils are usually needed only every two or three years to provide control of scales and mites. Sure, the populations will build up in the off years, but should remain relatively low if the three-year program is followed. Superior oils are lighter grade oils which won't cause as much burn damage during late spring, or even in-season, use. Superior oils will also provide control of the mites and scales.
The first regular spray of the year is applied when the green tissue is ½ inch out of the bud. This spray for homeowners usually consists of a multipurpose fruit spray (and sulfur if needed for powdery mildew). Multipurpose fruit spray has been re-formulated the last year or two to include malathion, captan, and carbaryl (methoxychlor was eliminated from the old mixture). This same mixture would be used when the fruit buds are in the pink stage (when fruit buds show color). After that, the persistence and consistence pays off as you spray with the same mixture about every 10 days until we get to within two weeks of harvest. In our area, we need to continue spraying this late because of apple maggot.
This spray schedule will also control borers on apples and pears, if you also thoroughly spray the trunk and main limbs of the trees. On non-bearing, young fruit trees where borers have attacked, you can spray the trunks every two weeks during June and July with a multipurpose fruit spray.
The spray schedule for peaches, nectarines, apricots, and plums varies a little bit. The dormant spray for them uses captan fungicide. This is the only spray that controls leaf curl and plum pockets. The next spray is when fruit buds show color with captan, followed by captan at bloom. When the husks begin to pull away from the base of the fruit we would then spray with sulfur, captan, and malathion. This mix would then be used every 10 days or so to within a week of harvest.
For borers on the peach group, you can spray or paint the trunk only with carbaryl (Sevin) on June 15, July 15, and August 15. We walk a tightrope with the loss of some of the insecticides since carbaryl can cause fruit drop or thinning on the peach group and some apples.
March 4, 2010
They aren't the "monsters of the deep," but it certainly seems like it to hear some people talk about them. The "them" is the Asian ladybugs. Each day we get a little bit of sun, or slightly warmer temperatures, we have a few more break dormancy and find their way into your coffee cup or inside your reading light.
We had a tremendous buildup of the adult beetles last fall, mainly to prey on the soybean aphids present just before harvest. Then the soybeans died, causing the soybean aphids to die as well. Looking for more food, the ladybugs found their way to your house. There they sought shelter to overwinter, and warmth brings a few of them back to the active status each day. One of these days we will be overwhelmed when the temperatures are warm and the sun shines brightly.
As for what to do, inside the house you suck them up with a vacuum, pick up with toilet paper and flush accordingly, or use the swatter. Larger problems can be helped somewhat with a flying insect spray in an aerosol can to take out the ones it hits. No-pest strips can be used in areas such as three season porches where you aren't spending much time now, but don't use them in areas you frequent. Area sprays on the sides of garages and so forth will be effective soon. You'll still have plenty of the invaders, but you might feel better after getting revenge on their relatives.
March 4, 2010
We are rapidly approaching the end of the pruning season for most fruit trees and deciduous ornamentals. There are a few rules that are recommended for pruning, and there are several other items that are up to "pruner discretion." One of the beginning items to discuss is the equipment.
Most pruning can be done with three pieces of equipment. The most used piece is a pair of bypass pruning shears. These shears will cut up to about 3/8 inch comfortably, and make sharp cuts that don't tear or crush. There are still anvil type shears available, but their use is mainly in vineyards to girdle grape vine ends. The second piece of equipment is a bypass lopper. Loppers can cut up to about 1.5 inch wood, depending on the type and size. If you have the money, a good set of compound action loppers would be a good investment. The third piece of equipment is a pruning saw. These can come in several shapes, sizes, and price ranges. For smaller limbs, a folding or straight pruning saw is a good buy. For larger limbs, a bow saw may be needed. The maneuverability and ease of use are key points when selecting a saw.
The time of year we prune various trees and shrubs is important. Most trees and shrubs that aren't flowering in nature should be pruned between December and mid-March. Flowering trees and shrubs should be done after they flower. Evergreens are best pruned in late June. With oak wilt in the area, oaks should be pruned in December to lessen sap flow, which attracts virus-carrying beetles. And, any branch that hits you in the face when you are mowing should be cut off immediately (except on those oak trees)!
Basic pruning should serve to remove poor branches, keep the plant growing aggressively, and do a little bit with shaping a plant. Poor branches mean bad angles from a trunk or main branch, dead branches, branches that rub together, or multiple leaders. As far as keeping a plant growing aggressively, remember that pruning is a rejuvenation process. Regular pruning also produces more two-year-old wood that produces fruit on fruit trees, and flowers on flowering trees and shrubs. Minor shaping and sizing are possible, but major changes probably mean a different plant should be selected.
When making a pruning cut, the key is to cut back to something. Branch tips can be cut back to a bud, and entire branches can be cut back to another branch or the main trunk. When making the cut to a branch or trunk, cut to the edge of the collar (about a 1/16 of an inch from the other branch). Cutting too close to the other branch destroys the water carrying tissue, and leaving a stub will guarantee a rotten branch stub (that will eventually rot into the main branch or trunk). Topping a tree lessens weight, and reduces size, for a short period of time. Within five years of topping, you will generally have more weight and growth than you would have had without topping. If you are making cuts on large branches, it is best to cut once about 18 inches from the main branch, then make a second cut to leave the 1/16 inch collar. This will help prevent the cut branch from tearing other branches.
Hopefully these basic pruning hints will help you get started on the right foot. Remember the golden rule of pruning "If you think you've cut out too much, you're probably about right."