Roses

 

Q. Why are my roses more fragrant at certain times?

A. Roses are often more fragrant in warm, humid atmosphere, and during the brief time before a summer storm. Drought, extreme heat, or very cool days diminish the fragrance of roses.

 

Q. What is the best time of the year to transplant roses?

A. The best time to transplant is either in the fall or in the early spring when the roses are dormant, and the ground is workable.

 

Q. What is the best time to prune roses?

A. The best time for pruning is early spring, just before new growth starts sometime after the last killing frost.

---

Trees

 

Q. Do all trees have tap roots?

A. In sandy, well-drained soils some trees such as oaks and pines develop deep roots directly beneath the trunk. These are commonly called tap roots. Many trees never develop tap roots. When the water table is close to the soil surface or when the soil is compacted, tap roots do not develop. Tap roots generally do not form on trees planted in our urban landscapes.

 

Q. Do roots grow only to the edge of the branches or dripline?

A. Trees growing in the woods have root systems reaching well beyond the edge of the branches. Frequently, roots extend from the trunk as far as the tree is tall. Roots on trees and shrubs planted in a landscape grow to 3 times the branch spread within 2 or 3 years after planting if soil conditions are favorable.

 

Q. Is it true that the canopy and roots of a tree are a mirror image?

A. The latest research indicates some 90% of the root system is in the top 12 inches of soil. In many wooded areas, virtually all the roots are within the top 6 inches of soil.

 

Q. Will roots circling around a container continue to grow in a circle once the tree is planted?

A. Roots frequently circle within the perimeter of a container several times before the tree is planted into the landscape. The portion of the root which grew in the container does not straighten out, but new growth on this root will not continue to circle.

 

Q. Will a small trunk wound inflicted by heavy equipment during construction or at any other time cause major injury to the tree?

A. Trees cannot replace injured tissue (heal) like animals; therefore injury permanently reduces the trees capacity to fight future stress caused by insects, disease or other factors. In addition, many roots are destroyed as heavy equipment operates over the root system. Even one pass over the root system with a bulldozer, earth scraper or other piece of heavy equipment can cause significant root damage. Do not allow equipment to operate within the dripline of trees which are to be saved.

 

Q. How do you protect a tree during construction?

A. Tree roots extend to 3 or more times the dripline of the tree. Approximately 50% of the root system is located outside of the dripline. No equipment should operate within this area if the tree is to be saved. Sturdy fences should be constructed at the dripline to encourage enforcement of this guideline. This serves as the best guide to help prevent construction related tree decline.

 

Q. Can grading to prepare a site for laying sod or planting shrubs harm trees?

A. Since many of the fine roots are located close to the soil surface, changing the soil grade by as little as 6 inches can cause extensive damage to the root system of existing trees. Design the landscape to largely fit the existing grade. If grade changes are necessary close to a tree, remove the tree and plant several younger, healthy trees.

 

Q. If a tree survives the first 2 to 4 years following construction, can it still die from construction related injuries?

A. Trees frequently decline after construction of a building. Often, branches begin dying within a year or two due to severe root damage. The tree may be dead within 3 or 4 years. However, it is not uncommon for trees to show a slow decline over a 5 to 15 year period. The tree may not show obvious signs of decline for many years, but, following a drought period branches may quickly lose leaves and begin a rapid decline. The tree may be dead a year or two later.

 

Q. Since trees do not heal are they capable of isolating injured tissue from healthy wood?

A. They lose the storage capacity and function of injured tissue forever because cells cannot be replaced. In contrast, animals heal by replacing injured tissues. Plants must seal off the injured tissue from the healthy portion of the plant in order to stay alive. The swollen callus tissue developing around a trunk wound or pruning scar is closing over the injured tissue, not healing.

 

Q. Should pruning cuts still be flush with the trunk?

A. It has been standard practice to prune a branch flush with the trunk. Extensive research has shown that this practice injures the trunk and is extremely detrimental to tree health and shortens the life of trees. Flush cuts make a tree more susceptible to frost cracks, heat injury, root problems, cankers and sprouting. To avoid this, always cut to the outside of the branch collar which is located at the base of every branch. This collar is easily seen as a swelling where the branch meets the trunk. When pruning in this manner it may appear as though a stub is left on the trunk; however, properly done, this technique removes the entire branch and does not injure the trunk.

 

Q. Do wound dressings and pruning paints prevent wood rot?

A. Wound dressings do not prevent wood decay behind a pruning cut. They provide no benefit to the tree. Some research indicates that wound dressings promote decay in certain situations. Only proper pruning practices prevent wood rot.

 

Q. When transplanting trees do we benefit from amending the backfill soil?

A. The soil removed from the planting hole should be used to fill in around the root ball. No amendments should be added to the backfill soil, since it does not improve survival or growth after planting. Apply 2 to 3 inches of mulch after transplanting around the base of each plant.

 

Q. Should trees be pruned at transplanting to compensate for root loss?

A. Pruning the shoots and branches to compensate for root loss in field grown trees is not recommended. The signal initiating root regeneration originates in the shoot tips. Pruning removes shoot tips and therefore reduces root regeneration. Begin corrective pruning one year after planting.

 

Q. Do established trees need to be fertilized in order to maintain their health?

A. Established trees growing in a maintained landscape receive enough fertilizer for moderate growth because their root system grows into fertilized shrub beds and turf areas. In most instances, additional fertilizer is not necessary to maintain healthy trees. Some trees with micronutrient deficiencies respond to applications of minor elements.

 

Q. Does tree fertilizer need to be injected into the soil?

A. Tree roots grow among turf and shrub roots. Most are located within the top 12 inches of soil. Fertilizer broadcast over the surface reaches tree, shrub, and turf roots in adequate amounts.

 

Q. Does fertilizing in the fall stimulate growth in the fall susceptible to winter kill?

A. Fertilizing trees in late summer and early fall may stimulate late-season growth which is more easily winter-killed. Fertilizer applications should be based on soil tests. If a deficiency is determined by a soil test late in the season a late fall application, after the plant has gone dormant, may benefit the plant. Many trees and shrubs will not respond to an application of fertilizer until the following year.