Fertilizing Your Annuals

When perennials bloom poorly or produce little or no seed, they can try again the next year. Unfortunately, annuals don't get this second chance. Annuals work hard to form flowers, and a little help from you will ensure they provide the best show possible.

Like other plants, annuals need the big three nutrients (nitrogen, phosphorous, and potassium). Healthy soil that is rich in organic matter provides the basic nutrition most plants need, but some annuals will want a boost, especially if they are grown in pots. Every time water drains through the hole at the bottom of the container, nutrients in the soil are carried along with it, and they should be replaced.

Periodic applications of fertilizers containing all three major nutrients will ensure that your annuals are well-nourished. For flowering annuals, use an all-purpose plant food that will provide them with the phosphorous and potassium they need to realize their blooming potential. Foliage plants will flourish with a formula higher in nitrogen (the first of the three numbers in a fertilizer formula).

Types of Fertilizer

Whatever type of fertilizer you choose (granular or liquid, synthetic or organic) remember to follow the directions on the package for how much to use and how often to apply it. Overfertilizing is worse for plants than feeding them too little. Too much fertilizer causes rapid, weak growth that is susceptible to damage by pests and diseases, and excess fertilizer may run off and find its way into the water table, causing pollution.

Granular Fertilizer

For annuals in beds and borders, granular fertilizers are one option. Spread granular fertilizers over the soil around the plants and scratch them in lightly before watering. You can apply synthetic granular fertilizers at planting time and periodically throughout the growing season. It takes more time for the nutrients in organic fertilizers to become available to plants, so these fertilizers are usually applied in spring before planting.

Liquid Fertilizer

Liquid fertilizers are ideal for potted plants. There are a number of liquid fertilizers on the market that are environmentally safe yet contain the nutrients needed to ensure good plant growth. During application, you can either follow the instructions on the package or dilute the concentrate to half the recommended strength. A half-strength solution will still provide adequate nourishment while keeping you from overfertilizing your plants. Simply apply your liquid fertilizer every three or four weeks for best results.

Pruning Mature Trees

Common reasons for pruning trees are to remove dead branches, to remove crowded or rubbing limbs, and to eliminate hazards. Trees may also be pruned to increase light and air penetration to the inside of the tree's crown or to the landscape below. In most cases, mature trees are pruned as a corrective or preventive measure.

While routine thinning does not necessarily improve the health of a tree, if we want trees to complement other landscape plantings and lawns, some pruning is occasionally required. By following proper pruning techniques, you can maintain good tree health and structure while enhancing the aesthetic and economic values of your landscape.

When to Prune

Most routine pruning to remove weak, diseased, or dead limbs can be accomplished at any time during the year with little effect on the tree. Just remember that heavy pruning just after the spring growth flush should be avoided. At that time, trees have just expended a great deal of energy to produce foliage and early shoot growth. Removal of a large percentage of foliage at that time can stress the tree.

Making Proper Cuts

Pruning cuts should be made just outside the branch collar. The branch collar contains trunk or parent branch tissue and should not be damaged or removed. If the trunk collar has grown out on a dead limb to be removed, make the cut just beyond the collar.

If a large limb is to be removed, its weight should first be reduced. This is done by making an undercut about 12 to 18 inches from the limb's point of attachment. Make a second cut from the top, directly above or a few inches farther out on the limb. Remove the stub by cutting back to the branch collar. If you're unsure if you can handle a large project, always contact a professional.

How Much Should Be Pruned?

The amount of live tissue that should be removed depends on the tree size, species, and age, as well as the pruning objectives. Younger trees tolerate the removal of a higher percentage of living tissue better than mature trees do. An important principle to remember is that a tree can recover from several small pruning wounds faster than from one large wound.

A common mistake is to remove too much inner foliage and small branches. It is important to maintain an even distribution of foliage along large limbs and in the lower portion of the crown. Overthinning reduces the tree's sugar production capacity and can create tip-heavy limbs that are prone to failure.

Mature trees should require little routine pruning. A widely accepted rule of thumb is never to remove more than one-quarter of a tree's leaf-bearing crown. In a mature tree, pruning even that much could have negative effects. Removing even a single, large-diameter limb can create a wound that the tree may not be able to close. The older and larger a tree becomes, the less energy it has in reserve to close wounds and defend against decay or insect attack.

Prune your mature trees only to remove dead or potentially hazardous limbs and you'll be able to enjoy them for many more years!