Down the Garden Path

Richard Hentschel Extension Educator

Our typical spring of several weeks has pretty much been compressed into those two weeks of 70+ degree temperatures that have just passed for our early spring bulbs. Sure we still have our flowering shrubs and trees to bloom yet, but unless the weather moderates and remains cooler those blooms will come and go just as quickly as our spring bulbs. Those warm temperatures really accelerated our early spring pruning and early sprays of fruit trees and any dormant shrub pruning that needed to be done. Fruit growers will need to stay on top of their sprays based on plant development, not the typical calendar that we normally base those treatments on.

Right now the lawns are growing and need to be mowed just as soon as possible if you have not already mowed once or twice. If you have not walked your yard, you are going to be surprised how long the grass already is. You may need to mow with the mower set on the highest cut possible and come back in a day or two and mow at your normal height. Kentucky Bluegrasses should be cut at a height or 2.5 to 3.0 inches. If you can readily see clipping laying there, consider raking them off the lawn and using them in the compost pile if you have not used any herbicide yet this year other than a crab grass preventer.

The soil in the vegetable garden could be worked up and any organic matter can be worked in at the same time. We still need to resist planting too early. Unless you are planting some of the hardiest vegetable transplants or potato seed pieces, be patient. The early vegetables from transplants or seeds are Cabbage, Broccoli, Lettuce, Peas, Radish and Spinach.

Even in Northern Illinois gardeners can grow multiply crops of the same vegetable to extend our harvest season. Vegetable plants that like to grow in the cold and cool temperatures of spring will also like the cool cold temperatures that we have in the fall.

Most likely we have all have seen a lot more insects out and about too. Insects develop in the spring as temperatures rise and right along with their host plants. Our milder winter temperatures have allowed more insects to survive the winter and that could mean more of them during the summer and since they started earlier be here longer as well, perhaps having an additional generation. It will be a worthwhile to keep a look out for those insects that are truly a problem in the garden. For vegetables that could be aphids, flea beetles, tomato hornworm or any of the cabbage worms. In the landscape that could mean the spring and fall webworms, Japanese beetles, aphids and related pests like slugs. Just like in a typical year, just because you spot them, does not mean you need to manage them if the damage is minimal and you get plenty of vegetables to eat out of the garden anyway.

If you have questions about your garden plants, Master Gardeners are available to help you identify the pest and offer management suggestions.

Down the Garden Path

Richard Hentschel Extension Educator

The warmer weather has had our lawn grasses turning green and with that a grass weed that prefers even warmer temperatures of summer going. This past week Extension Master Gardeners have seen quite a few samples of Nimblewill. Nimblewill is a warm season perennial grass that creeps by above ground stems in a loose matt among the other lawn grasses. Each node that forms a leaf can also form roots and that helps it spread. Some homeowners have described it over the phone as looking wiry. Right now those patches are light tan in color or sometimes described as straw colored and clearly stand out in the greener grass. It likes shady or wet areas in a lawn to get established. Many of our cool season grasses are dormant or slow down in growth while Nimblewill marches ahead without any competition.

Nimblewill is very different in appearance than Zoysia grass, our other warm season grassy weed that can be found in the lawn. Right Zoysia is a golden tan color in the lawn and grows very slowly as it moves into the lawn.

For many years, a homeowner had little to use against this weed. In recent years, non-selective herbicides have been used to manage the weed and any desirable grasses in the area treated. Later, over seeding or sodding was done. A homeowner would have to spray out an area larger than expected to be sure that the weed was eliminated. The other choice was making sure proper cultural practices were done to make the lawn more competitive and prevent Nimblewill from establishing.

Commercial Lawn Care companies now have a product that will selectively control this grass weed in our lawns. The treatments need to take place while the weed is young and actively growing in the late spring to early summer. It will not necessarily be a one-time treatment like dandelion control. It can take 2 or 3 treatments to get good control and there are side effects too. There can be discoloration to the desirable lawn grasses. Spot treatments are often done to lessen this discoloration. If Nimblewill is a big enough concern in your lawn, consider having the weed professionally treated or take on the weed as you have in the past, by improving the lawn through healthy practices and spot treatments while the Nimblewill is actively growing in late Spring.

Down the Garden Path

Richard Hentschel Extension Educator

A great many of our ornamental flowering trees and shrubs have the 2012 bloom ready to go right now. If you are already outside doing your early spring pruning on your apple trees, bringing some of those branches that have flower buds will get you two bloom shows too. Typically our ornamental landscape plants produce the next seasons blooms starting not too long after they have completed flowering, those landscape plants are already hard at work producing the next seasons' spring flower buds. This spring the landscape plants are really coming out of winter dormancy very quickly.

Outside in your yard as our temperatures continue to moderate, the flower bud scales protecting the flower blooms slowly begin to soften and loosen. About this same time, sap flow begins to move upwards into the flowering tree or shrub from the root system. If gardeners continue to observe the buds on their favorite landscape tree or shrub, they will begin to see the buds swell in size. This is yet another indicator that spring is coming in 2012 way ahead of 2011.

As a gardener in the family takes to the yard to do that early spring pruning, those branch clippings could be brought indoors and if there are flower buds there could be forced for your enjoyment inside and will last for a few days to a few weeks. After that our earliest bloomers will be starting outdoors in the yard where the bloom show really gets going.

The best tactic is to remember that in nature the bud scales protecting the flower bud naturally soften from the spring rains allowing the flower bud to emerge as easily and quickly as possible. Gardeners can wrap the branches in moist materials that are readily available like old rags, paper toweling, just about anything that will keep the bud scales moist and softening. This should be done on the cooler side of temperatures, just like outdoors. You will have to experiment some to figure out how long you moisten those buds, usually a few days is enough. Once those flower bud scales soften and you bring those branches into the home, then warmer temperatures will allow the flower buds to expand and the bud scales will begin to slough off.

Gardeners can start the forcing process over and over again, providing a succession of bloom, using new clippings each time. Gardeners can experiment with more than one kind of flowering shrub or tree at the same time or keep them separate for a larger more impactful display. Ornamentals like Forsythia and Amelanchier will take about a week to force, Redbuds, Privet and Pussy Willow two weeks. Honeysuckle, Flowering Almond and Slender Deutzia will take about three weeks to force. Lilac, Spireas and Crabapples will take about four weeks.

Once the blooms fade or you have more coming that look a lot fresher, those branches and twigs can be added to the compost pile.

Down the Garden Path

Richard Hentschel, Extension Educator

Dormant pruning is always begun once the weather moderates and allows gardeners out in the home landscape without being bundled up and while we still have considerable cold weather. The days warm up letting us prune, while the nights are around 32 degrees. If you are a home orchardist, you know the clock is ticking now with warmer temperatures we have had. It is time to make sure those apple tree scaffolds are ready to go and be able to hold the fruit load later in the summer. With the mild winter, fruit growers may expect to see even more flowers becoming viable fruit this year that will need to be thinned.

Many landscape plants can be pruned while dormant and the job is even easier because they are dormant. Visualizing what you want to prune or how you want the plant to look like after pruning is easier since we can readily see the plant structure right now. Some of fine textured smaller foundation plantings of Spirea and Potentilla that have not been looking too good the last couple of seasons will benefit from rejuvenation pruning, creating a brand new plant in a single season. With some shrubs gardeners will not even miss a bloom show if the flowers are formed on current year wood. Sometimes when rabbit damage has been particularly bad, rejuvenation pruning is the easiest way to help the plant recover from severe rabbit feeding over the winter.

Other larger shrubs may be best pruned using the renewal method, removing a few of the larger, older stems at or very near the soil line. This kind of pruning leaves most of the shrub standing and if that shrub blooms on older wood, you get the see the blooms even this year. When you renewal prune, three benefits happen. The first is that the oldest wood is also the tallest branches, so the plant is naturally going to be a little shorter. Benefits two and three really go together. That older wood is the part of the plant that is most likely going to insects or disease in or on the wood. By removing those older branches, gardeners reduce the populations of insects like scale that have built up over several years. Older wood is less vigorous that newer wood and can be more disease prone too. Older wood is often a different color than newer, younger wood or has a heavier bark while younger wood the bark is still smooth. A good rule to remember is that where you prune is where the new growth will occur. If you keep this in mind when pruning, where you make the cuts will make a lot more sense whether you are using the rejuvenation or renewal method of pruning.

Pruning is going to be easier and less tiring if the pruning tools are clean and kept sharp. Young plants may only need a good pair of by-pass hand pruners to take care of any pruning they need. As landscape plants begin to mature, our tool of choice may need to be long handled pruners that give the leverage needed to prune a heavier woody branch. Once the plants have outgrown using long handled pruners, turn to your pruning tree saw.

Master Gardener are nearing the end of their training for 2012 and are anxious to begin to work with county residents by answering the many Spring gardening questions that are sure to come up as the gardening season begins .

Down the Garden Path

Richard Hentschel, Extension Educator

The past year there has been quit a buzz among plant pathologists and entomologists about the national spread of yet another potentially devastating tree disease in the United States.

Thousand Cankers Disease (TCD) has been declared to be a viable threat to walnut trees in Illinois, so much so that in early February, Governor Quinn approved regulatory measures to monitor and restrict the movement of walnut wood that could be carriers of TCD. Like the Pine wilt nematode is being spread by the Sawyer beetle and Dutch elm disease being carried by the Elm bark beetle, TCD is spread by another insect, the Walnut Twig Beetle.

The disease itself is a fungus that is spread as the Walnut Twig Beetle is feeding just under the bark in the phloem cells. As the fungus grows under the bark, the cells die forming a cancer that leads to decline and eventual death of the Walnut. There will eventually be "thousands" of these cancers in the tree.

Right now this disease has not been detected in Illinois, yet as history would show, we seem to be adept at unknowingly transporting insects and diseases. A most recent example is the Emerald Ash Borer. The regulations are being put in place to prevent the disease or insect from entering Illinois. Similar to the restrictions placed on those dealing with ash wood and products made from Ash, those individuals and companies dealing with walnut lumber and products made with walnut must follow and comply with very specific guidelines that would allow walnut into Illinois. Walnut nuts, Kiln dried lumber without any bark attached would be allowed. There are more products allowed, depending on the product using walnut. If you are a wood worker, any walnut that your hardwood supplier or you have in stock should be fine if it has been in your or their possession for some time. Master Gardeners will have information about TCD available during the growing season. If you are concerned that your walnuts may be infected in the future, the Illinois Department of Agriculture will be the official organization.

For more information regarding TCD, visit the Illinois Department of Agriculture website at www.agr.state.il.us and click on the Thousand Cankers Link on the right or click on this direct link.  Thousand Canker Disease and Walnut Tree Beetle

Down the Garden Path

Richard Hentschel, Extension Educator

The garden catalogs have been out on the table awhile, maybe even "dog eared" a bit form all the reading and circling of plants you are considering. Hopefully some of those circles have been around the herbs that flavor our food or make our homes more inviting. Herbs are pretty versatile when it comes to getting them grow. Herbs do well in containers on the patio or in the ground in the garden or a spot just outside the kitchen or back door. A newer trend is to get the herbs into the landscape, where you do not have to make a new bed. Any herb can be in the landscape, yet some gardeners will create a color garden within the landscape bed using herbs like wormwood and artemesia.

Culturally herbs are easy to grow. Since they typically naturally contain oils, most insects leave them alone. Like vegetables they do best with lots of sunlight during the day and a well drained soil. Herbs do not require a high level of soil fertility, so that can be a bonus if the location you have does not have the best soil.

If you like to cook, herbs like sage, basil, thyme, dill and tarragon make a lot of sense to grow. Fresh herbs in a meal can really add some punch to the flavor of dish. If you want to go out in the yard and smell the herbs you have, then a scented garden should be planned using mints (watch out because they can spread), lemon balm, and scented geraniums.

Growing herbs in a container means the potting soil should have good drainage, just like your flower pots. Water them well until water comes out the bottom of the pot. If you have a saucer beneath, empty that after a few minutes so the roots do not remain water logged. Herbs grown in the ground will need little more than water and sunlight. Herbs grown in a container will need some fertilizers to maintain good growth given the limited soil they have to grow in.

Herbs can be annuals or perennial forms. Container gardens will likely contain mostly annuals since it will be harder to over winter a perennial in a pot. Annual herbs will need to be harvested regularly, sometimes more often and in amounts greater than you need in the kitchen. These can be dried and used at a later time. When harvesting your perennial herbs, more of the plant will need to be left in place. You can expect to harvest the perennial herbs a couple of times a season. The first harvest should be done just before the plants flower for best flavor content and then again late summer. Many gardeners will harvest and dry the second time for use later in the colder months.

There are many ways to dry your herbs and much has been written on that subject. The basic idea is to remove the moisture as quickly as possible. The internet will reveal methods for tray drying, drying with artificial heat, and bag drying. There is even a way to do prepare the fresh herbs for freezing.

If you have not yet circled any herbs from the catalog, reconsider what might end up in your garden this year and experiment with just one or two of the more common ones or put in a musical garden of Parsley, Sage, Rosemary and Thyme.