Spring is a great time to prune trees in the orchard or in the landscape. Most of us think of pruning as the removal of branches and twigs. That is true but pruning also stimulates new growth and how we do it will determine the direction of that growth.

We prune landscape trees to improve their shape, remove potentially dangerous growth and to try to limit size. Fruit trees are pruned to improve the yield of fruit. Each type of pruning has its own goals and techniques.

When pruning apple, peach, pear and other fruit trees we want to establish several strong, fruit-bearing branches called scaffolds. We also want to open up the canopy so that sunlight and sprays may penetrate into the interior of the tree. A well pruned fruit tree may appear “butchered” to the average homeowner. In fruit trees, beauty is found in an abundant crop of well formed fruit next fall.

Landscape trees are pruned for aesthetics and safety. If you plant the right tree in the right site, you should have to do very little pruning. Given enough space and separation from houses, driveways, streets and power lines, most trees will grow just fine on their own.

Pruning trees is both an art and a science. The science consists of understanding how trees grow and how to guard their health. Art involves being able to imagine what the tree will look like six months after you prune it.

Following a few general rules will help guarantee success in pruning trees. One of these is to avoid leaving stubs. When using hand pruners, cut small branches back close to the larger stem. Small tubs will only die and provide a place for insects and diseases to enter the plant. Plus they will interfere with your enjoyment of the tree. Stubs are ugly.

Speaking of pruners, one key rule is to keep all blades sharp. A wide range of  hand pruners, loppers and saws are available. The most important factor is to buy good quality equipment which will hold a sharp edge. Dull pruner blades will cause ragged cuts which do not close easily and look awful. Cheap equipment tends to be made of lower quality steel and is more difficult to keep sharp.

In the olden days, we used to apply a thick, tar-like compound to the larger wounds created by pruning. Research has shown that these compounds may actually cause more harm than good. They seal moisture next the wound and this may encourage rot and other fungal problems. So, the general recommendation is to avoid using pruning sealants.

There are two exceptions to the rule. One is when pruning peach trees. Since peaches are susceptible to an insect borer that enters through wounds, sealants are often used to protect them. The other exception occurs when pruning red oak trees.

Oaks and more specifically, primarily red oaks, are susceptible to a serious disease called oak wilt. This fungal disease is spread by small beetles visiting an infected tree and then flying off to another tree. The insects are attracted to fresh, open wounds so the recommendation is to avoid pruning oaks during the growing season. If you absolutely must prune them when the leaves are present, use a sealant to cover the wounds. Otherwise, prune oak trees during the dormant season i.e. when the leaves are off, and the insects are not active.

Finally, avoid pruning spring flowering shrubs such as lilacs, forsythia, rhododendrons, magnolias and others until after they bloom. Shrubs that bloom in April and May develop flower buds the previous autumn. To prune them now will only reduce the number of flowers for your enjoyment.

Animals, including we humans, feed on this plant material and convert that energy into proteins and other tissues. We can gain transfer the energy of the sun into our bodies by eating either plant or animal materials.

As an animal, if I eat pounds and pounds of sugar filled donuts or steaks, I will grow bigger. On the other hand, if I apply more and more fertilizer onto my plants, they may or may not grow. They can only use these nutrients if the levels of light, chlorophyll, water and temperature are at the required minimum for that particular plant species.

If I put too much of some types of fertilizers on my plants, they may even die. This happens because many of the elements needed by plants fall into the “salts” category of chemicals. If a clump of granular fertilizer or a wad of fresh animal manure comes into the contact with plant roots, it may cause the plant to “burn”. What is really happening, of course, is that the salts in the fertilizer or manure will pull the water out of the roots and cause them to die. As a result, the leaves and stems that were relying on those dead roots for water must also die.

Before starting a garden, lawn, flower bed or other planting, it is a good idea to take a soil test. The results will show how much phosphorus, potassium, calcium, and magnesium is present in the soil. It will also give you the pH, the type of soil and a specific fertilizer recommendation for the proposed crop i.e. flowers, fruit, vegetables, lawn, etc.

On a standard soil test, however, nitrogen levels will NOT be tested. This is because nitrogen is very water soluble and moves through the soil quickly. The amount present in your soil may vary greatly over short periods. So, by the time the soil test result gets to you, the level of N may have changed considerably.  The sample results will make a nitrogen recommendation based on the amount commonly needed by the crop to be grown. For examples, a typical Kentucky bluegrass lawn will generally need 3 to 6 pounds of nitrogen per 1,000 square feet per summer depending on whether it is irrigated or not.

The other major nutrients such as phosphorus or potassium are held more tightly by the soil particles and remain more constant in the soil over the growing season. Many soil tests, especially in areas with clay-type soils, will report high levels of potassium or phosphorus in gardens or beds that have been routinely fertilized. In such cases, the fertilizer recommendations may show that no more needs to be added for that growing season.

If you go to your local garden center, you will find that most fertilizers have three numbers on the label. An example would be a 12-12-12 fertilizer which would contain 12% each of nitrogen (N), phosphorus (P) and potassium (K). In a 100 pound bag, we get 12 pounds of each of these three nutrients. (Technically, it is a little more complicated than that but the home gardener does not have to worry about it since the recommendations take the chemistry into account for you.)

If your soil test says that you only need to add nitrogen or just nitrogen and phosphorus or nitrogen and potassium, there are special fertilizers available to fill these needs. Generally, these are called single nutrient fertilizers. They may be purchased separately and used in combination to meet your specific needs.

When only nitrogen, for example, is needed, there are several alternatives. Ammonium sulfate has an analysis of 21-0-0 (21% N) and is preferred by plants such as rhododendrons, azaleas and blueberries that need an acid soil. Urea (45% N) and urea formaldehyde (38% N) are synthetic organic compounds that give a slightly acidifying effect. Sodium nitrate (16% N) and calcium nitrate (15% N) cause the soil to become slightly less alkaline. You can tailor your selection based on the pH of your soil and the type of plants you are growing.

Phosphorus is held tightly to clay particles in the soil. If the soil test calls for more P, it is applied in the form of the chemical compound called phosphate, P₂O₅. Rock phosphate (30 to 36% P₂O₅) is a natural fertilizer that releases the phosphorus very slowly. When the pH is above 6.0, it becomes very water insoluble and not available to the plants. Concentrated triple superphosphate (46% P₂O₅) and regular superphosphate (20% P₂O₅) are the most commonly used single source of phosphorus.

Potassium may be lacking occasionally in soils. It is held tightly by the soil but not as much as phosphorus. It is applied in the form of the chemical compound called potash, K₂O. Muriate of potash (60% K₂O) is the most common source for the home gardener.

Magnesium and sulfur may be derived from common Epsom salts (10% Mg and 14% S). Magnesium is part of the chlorophyll molecule and a deficiency in the soil may lead to yellowing of leaves.

These elements are all part of the group commonly called macronutrients. Plants must have them in relatively large quantities in order to grow properly. Another group of elements called micronutrient or trace elements, are also required for plant growth but in much smaller amounts.

Iron (Fe), zinc (Zn) and copper (Cu) are micronutrients that are commonly applied as a chelate. A chelate is a synthetic organic substance that slowly releases the micronutrient and thus makes it available to the plant for a longer period. When these elements are applied in the normal inorganic salts form, they are not as available to the plant roots. Manganese (Mn) is the one exception where it is better applied as a salt rather than a chelate.

As represented by the high percentage numbers on these fertilizers, each product has a high level of salts present. Therefore, it takes only small amounts to accomplish the task. For instance, a standard application of nitrogen is usually 1 pound of N per 1,000 square feet of area. If you are using Urea at 45% nitrogen, you would only have to apply 2.2 pounds to 1,000 square feet. That is a relatively small amount to spread evenly over a fairly large area. If too much is applied close to the plant, it will “burn.” So, take care when applying these concentrated fertilizers onto or near growing plants.

Seedlings of the boxelder tree (Acer negundo) have prominent “leaves of three” and are often mistaken for poison ivy.  As they grow, however, they soon form a tree-like central stem and stand upright on their own. Poison ivy (Toxicodendron radicans) is a vine and needs something upon which they can grow such as a tree trunk or fence to raise their foliage toward the sun.

Douglas fir (Pseudotsuga menziesii) is not a fir (Abies species), however, Kirk Douglas was the star of Sparticus. Douglas fir was named after the plant explorer, David Douglas. It is a tree that somewhat resembles a hemlock (Tsuga canadensis) thus the genus name, Pseudotsuga. The specific ephithet, menziesii, is in honor of another famous plant explorer, Archibald Menzies. Gee, there some of these scientific names actually do have some rhyme and reason.

Dutch elm disease killed primarily American elms (Ulmus americana). The disease is believed to have come from Holland on some veneer wood, thus the name. You would be amazed at how many people think that it attacks “Dutch” elms when there is no such thing…as far as I know, anyway.

Oregon grape holly (Mahonia aquifolium) is not a holly (Ilex species). It may be from Oregon but the purplish fruit it develops are not good for making wine…at least not in the classic sense. I know that people make wine out of all kinds of stuff including dandelion greens so who knows.

The roots of black walnut trees (Juglans nigra) form a substance called juglone that is poisonous to many other plants. Tomato plants growing near walnut trees will often wilt and die in late July. However, many other plants do not seem to be affected. For those that are impacted by juglone, the chemical gets into the roots and soon gums up the water carrying vessels. Thus, the plants start to wilt during the hottest part of the summer when water demands are greatest.

Our beloved, Hostas used to be called Funkia after a guy named Heinrich Christian Funck. There was a rock group called the Funkadelics but I don’t think they had anything to do with hostas. Hostas were also called Plantain Lily but that too has been largely abandoned by the gardening public. Today it is simply, Hosta.

All azaleas (Rhododendron species) are actually rhododendrons (Rhododendron species). Only a small number of rhododendrons are azaleas. How do you tell the difference? Heavy duty fans of the genus have several ways they use to divide the thousands of species and cultivars of rhododendrons. However, one simple delineation is that rhododendrons generally bear their flowers at the tips of their stems. Azaleas generally have flowers all along the length of the stem too.

Spider mites are not insects. Insects have six legs. Spiders and their relatives have eight. Eight is Enough was a television program back in the 70’s. Perhaps the key here is to know that many of the commonly used insecticides are aimed at…guess what…six legged creatures. They may not be effective against the eight legged critters that are sucking juices from our plants. You can learn more about insects and even help us identify some…Name That Bug.

Staghorn sumac (Rhus typhina) has red berries borne at the tips of the branch. Poison sumac (Toxicodendron vernix or Rhus vernix) has white berries borne along the stem. Chuck Berry is one of my favorite singers. Poison sumac is almost always found in wet, swampy areas while staghorn sumac is usually found in higher ground.

Grape hyacinth are not hyacinths. They are in the genus Muscari. Their fruit makes lousy wine. See Oregon grape holly above for a discussion of wine makers.

Bats have their young during the first two weeks of June. The runt of the litter is always named Robin.

Yellowjackets, wasps and hornets live just one year. Only the queens survive the winter and re-establish new nests the following spring. The rock band, “Queen” minus their wonderful, late lead singer, Freddie Mercury, maintains a nest in England.

Roots, of course, are the lifeline of the plant. They transport water and nutrients up to the leaves as part of the photosynthesis process. Without these inputs, the plant cannot produce its own food and energy supply. Plants establish a natural balance between the size of the root system and the size of the above ground part of the plant. This assures the proper flow of water and nutrients up to the leaves. If stems are cut off, part of the root system dies back. If some of the root system is removed, parts stems and leaves will suffer damage or death.

What all this boils down to is that the key to successful transplanting lies in preserving and restoring the root system. The key rule is to take as much of the root system along as possible whenever you move a plant. Unfortunately, no matter how careful you are, the plant will always lose some of its root mass during the transplanting process. Just jostling the plant a little bit will cause the death of tiny root hairs in the soil and digging will often cut off even larger roots.

Most damage will occur when you dig up a plant in the garden for transplant. Plants that come from the nursery in containers will suffer less root loss because they have had time to grow a dense, healthy root system in the pot. Those less effective, larger plants are sold balled and burlapped which helps keep the root mass together during transplanting. However, the plants are handled, however, remember that the key is to take care to prevent significant root damage or loss.

So, you have handled that transplant with care but the next step is to get it into the ground properly. Here, the general rule is to place the plant at the same depth as it was growing at its previous site. Many plants are eventually killed by being planted too deep in the soil. Generally speaking woody plants such as trees or shrubs do not tolerate having their bark buried in the soil. The moisture will eventually rot the bark and kill the cambium layer. There is a wide range of tolerance for this problem and some trees may live for many years after being improperly planted. However, eventually, it will lead to the death or loss of vigor in the plant even if it takes ten years to manifest itself.

A vital part of the equation to prevent transplant shock is post-transplanting care. By far the most important factor is to keep the plants moist but not saturated i.e. waterlogged, during the first season or two after transplant. If the plants are allowed to get too dry, this will kill more roots and retard the root renewal process. In the extreme, this may cause the death of the plant. Overwatering will cause similar problems. Remember that roots need oxygen as well as water around their roots in order to thrive.

Generally, fertilizers are not of great importance during the immediate post-transplant period. Until the plant re-establishes its root system, it will not be able to use it anyway. Also, if the fertilizer comes into direct contact with the roots, it may actually kill them. This rapid dehydration caused by water moving quickly from the roots into the salts in the fertilizer granules is what we commonly call “burning.”

Preventing transplant shock sounds pretty simple. Preserve as much of the root system as possible and keep the plant moist as it grows new roots over the coming season. Unfortunately, it is often not that straight forward.

The condition of the plant when your receive it is generally out of your control. The plant may look all right but it may be in poor vigor from improper care during the previous growing season. Someone at the nursery may have accidentally dumped some extra fertilizer into the container that may be released after you transplant it. Poor watering practices may have damaged the root system in the container but the impact does not show yet. The plants may have been given rough treatment during transport and the effects don’t show up until much later.

You may water your plant regularly but put the water too far away from the root ball to do any good. The nursery where the plant was grown may have had a sandy soil and your soil is clay and the water does not migrated from one to the other very well. You may go on vacation in July and miss watering during the two hottest, driest weeks of the year.

In the end, you need to control those things that are under your control. Keep the area of the transplanted root mass moist but not waterlogged. Plant at the proper depth in the soil. Buy from reputable nurseries. Take care in handling transplants of any type. Do all these things and you will have success…most of the time.

Well,  the first thing to determine is the type of hydrangea being considered. Different hydrangeas have different flowering cycles and requirements. So, you need to know your plant.

Probably the most common landscape hydrangeas fall into the shrub category. Generally, those plants belong to one of two rather large species that each have fostered many named cultivars prized by the home gardener. Knowing the species of your hydrangea can go a long way to answering the lack of bloom question.

The so-called Smooth Hydrangea belongs to the species, Hydrangea arborescens. It includes the commonly grown cultivars of ‘Annabelle’, ‘Highland Lace’, ‘Eco Pink Puff’ and ‘Grandiflora.’ This species flowers on “new wood” meaning flower buds form on what grows starting in the spring of the current season.

There are a number of reasons why these plants may not bloom. Although these are shade tolerant plants, if the shade is too dense, they may not bloom. Also, if you prune the plants in late May or early June, you would be cutting off the flower buds. A third possibility is the excessive use of nitrogen fertilizers which may encourage a lot of foliage growth at the expense of flower production.

The large shrub or small tree called the Panicle Hydrangea, Hydrangea paniculata, also blooms on new wood. ‘Grandiflora’ and ‘Pee Wee’ are common cultivars of this type of hydrangea.

The beautiful Climbing Hydrangea vine, Hydrangea anomala subsp. petiolaris, flowers on current year’s growth

The second major species of shrub hydrangeas is Hydrangea macrophylla, which is also called the Bigleaf Hydrangea. So-called Hortensias, Lacecaps and Teller Series hydrangeas belong to this group. Commonly grown cultivars include ‘Blue Danube’, ‘Merritt’s’ series, ‘Nikko’, ‘Forever Pink’ and ‘Pink Beauty.’

Bigleaf hydrangeas set their flower buds on “old wood” tissue. This means that, in the autumn, they set the buds which will become blooms the following spring.

When this type of hydrangea fails to bloom, it generally means that either the flower buds have died during the winter or were cut off by the pruning shears of an over eager gardener. Like most other spring flowering shrubs, these plants should be pruned just after they get done flowering and not during the dormant season.

The Oakleaf Hydrangea, Hydrangea quercifolia, flowers on old wood. In northern gardens, it will often survive but may not flower after a particularly cold winter depending on the individual site.