Sunday, March 29, 2009

Snow in March

What a shock to the system to wake up this morning to a snow frosted landscape. No working in the garden today. For deciduous trees that have not yet leafed out, this bit of heavy, wet snow is usually not a disaster. Down the street from me several trees have branches hanging over the street. If they had already leafed out the extra weight of the snow would have been enough to break them. This happened to us a lot in Colorado, where we once had snow the first week of June and sometimes as early as September. We would be out at midnight shaking the snow out of the trees.

Here it is the evergreens that take the brunt of these late snows. My neighbors have arborvitaes as a screen and over the years many branches have broken. Some are hanging over onto my side of the fence. You can take a broom or rake and gently push up on the branches to remove the snow. Where branches have broken you will need to prune them. This will aid the tree in healing over and reduce the opportunity for disease or insect damage later on. You can go to the Cornell University extension web site for a down loadable brochure on pruning to see how to do it properly.

It is also time to cut back your ornamental grasses. They can be cut back to about 6 inches. You might also give some thought about dividing them. They should be divided about every 2-3 years otherwise they die out in the middle and begin to look like a donut. Many perennials have this tendency if not divided frequently. It is actually a survival mechanism. As the middle dies and begins to decompose it provides needed nutrients to the remaining part of the plant. However, since I know you are very diligent gardeners and fertilize with a well balanced fertilizer every year and otherwise take good care of your gardens, it is an un-necessary task for the plant to do this and plants with holes in the middle are unsightly in the garden. So transplant regularly, (spring is great time to do this), and if you run out of room, find a friend who would like them or donate them to Habitat for Humanity.

And speaking of grasses, this year’s Plant of the Year, as selected by the Perennial Plant Association, is the Hakonechloa “Aureola,” otherwise known as Japanese Forest grass. I guess we don’t often think of grasses as being a perennial, but really they are and the PPA is to be commended for selecting a grass as this year’s Plant of the Year as they have become so popular in recent years. I would have thought that the Plant of the Year might have been a miscanthus, one of my favorite grasses, but the Hakonechloa does have a lot going for it. This grass is hardy in zones 5-8 (we are zone 5) and in our climate does well in partial sun and moist, rich soil. Its leaves are gold with green stripes and will lighten up the darker corners of any garden. It would also look good in a container, with some colorful coleus. It is also deer resistant, which is a definite benefit where we live. You can also go to the Perennial Plant Association web site to learn more about this plant and the PPA.

Wednesday, March 18, 2009

Clematis

Clematis are a great group of flowering vines that are adaptable to many situations. They are usually sold as “sun” perennials, but in fact there are many varieties that tolerate some amounts of shade. There are low growing “shrub” type clematis, clematis that bloom early spring, in the summer and several varieties that bloom in the fall. Most clematis have large, even huge, blooms and some with smaller, more dainty, bell-shaped blooms. Clearly, there is a clematis out there with your name on it.

What throws people off is how to prune it. Most plants are pretty forgiving with how we prune them, the worst that will happen is that you will accidently prune off this year’s buds and you won’t get any flowers for a year. So don’t be nervous… just follow these simple instructions:
Clematis can be divided into three types of plants: those that bloom in the spring, those that bloom in the summer/early fall and those that bloom twice, once in early summer and again in late summer (truth be told I have never had one of my twice blooming plants actually bloom the second time).

Group 1 plants bloom on old wood and should be pruned only after they have flowered for the year. These plants bloom early in the spring. Remove all the dead and weak stems immediately after flowering.
Group2 plants bloom on new and old wood so they bloom both in the early summer and then later on in the summer (maybe). Watch for swelling buds and carefully remove all dead stems above the swelling buds.
Group 3 clematis flowers only on new growth. These are the plants that flower in the early summer. These types of clematis can be pruned hard in February or March.

Here are a few other facts about clematis care:
Clematis prefer cool roots. Dig the hole about 2 feet deep and amend with organic matter. Set the clematis with the crown of the plant about 1 inch below the top of the hole. Back fill with the amended soil and water in thoroughly.
Clematis stems are very brittle. Tie the clematis to the trellis or what ever you want it to grow up and be sure to protect the base of the plant with screening material to prevent animals from damaging the stems.
Apply a layer of mulch over the winter months.

Here's another interesting thought when selecting clematis: you can plant several varieties together as shown in the picture on the right. You can select plants that bloom at the same time but in different colors or you can plant ones that bloom at different times so you always have something blooming. If you want to learn more about clematis, visit the greenhouse staff at Countryside.

Here are some varieties to try for shadier areas:

Alabast: Creamy white 5-6” flowers. Blooms May, June and August
Clair de Lune: 6-7” white blooms that turn to pale lavender. Blooms June, July and late August.
Elsa Spath- Rich lavender blooms, free flowering
Nelly Moser- pale pink with a red bar down the middle, blooms June and September
Lemon Chiffon- pale yellow cream
Viticella varieties: smaller 4-5” flowers, blooms profusely in July and August

Friday, March 13, 2009

Well, this past weekend would not have been a good one to spend out in the garden, but better weather will be here soon! Before things really get going, there are a few chores to be done prior to plants coming out of dormancy and that is pruning. Early spring is a great time to prune because the trees and shrubs have not leafed out and you can still see the branches and most plants heal more quickly in the spring than they do at other times of the year.

We prune for a variety of reasons. Pruning helps maintain the health of the plant. You can begin to control and train the growth of young trees and shrubs so that more drastic pruning doesn’t have to be done later. We also prune to rejuvenate shrubs, but sometimes replacement is the best option in these cases. Trees are a huge investment and add value to our homes, so it is worth spending the time to take care of them properly.

Shrubs: If you are rejuvenating a shrub do not prune more than of the plant during any one growing season. In most instances you will just be removing dead canes or giving a light shaping. In the early spring you can prune the summer blooming spireas, Rose of Sharon, dogwoods (those with colorful bark), privets, potentilla, St. John’s wort and snowberry. You could also prune the buddleia’s, caryopteris, and Russian sage, but here in our part of the country these tend to die back to the ground. Later in the early summer you can prune or shape the spring blooming shrubs such as lilac, rhodendrons, azaleas, and spring blooming spireas.

Trees: If you have mature trees it is probably best to call in a professional. They should send out a certified arborist to do the initial examination of the trees in question. They have the right equipment and experience to do the job right. There is a great pamphlet on the Cornell University web site called "An Illustrated Guide to Pruning Ornamental Trees and Shrubs". They also have information on pruning fruit trees for maximum performance. Pruning fruit trees is definitely a science.

Roses: I always wait until my roses start to bud out before I prune. This way I know exactly what winter damage has occurred. I prune down to the first outward facing bud break. This encourages the growth away from the middle of the plant. You really want to keep the middles as free from branches and leaves as possible. This way light can get all the way down to the lower branches and give the plant the greatest opportunity for photosynthesis as possible. This will lead to greater flower production and is better for overall plant health.

One thing that is really important when pruning is using the proper tools and having them well maintained. At Countryside, the greenhouse staff all use Felco pruners. The great thing about Felco pruners is the blades are replaceable. They are made from high quality steel so they maintain their edge longer and it is worth getting them sharpened. We totally abuse our pruners, cutting wire and plastic and all sorts of things we shouldn’t. Last year K.C.’s husband Duane sharpened all our pruners and that edge lasted all summer. If your budget can’t stand the Felco’s, Corona tools has several pruners that come close to the Felco’s and are not as expensive. Also the Corona tool website has two downloadable guides to pruning so check those out at http://www.coronaclipper.com/. (Lucky thing I always check these links. The first time I typed this in from memory I thought it was just "corona," which naturally took me to the Corona beer site.)

I was going to also cover pruning clematis but that is whole blog in itself so I will cover that next time.