Cultural Practices

Planting Care & Maintenance Advantages of Cultural Practices Disadvantages of Cultural Practices

Healthy hemlocks are not only more beautiful than stressed unhealthy ones, but they also stand a better chance of longer survival if they are attacked by disease or insect pests. Therefore, proper planting, care, and maintenance are important for the long-term health of your hemlocks. Cultural practices are management techniques that help to ensure healthy hemlock trees. They involve simple physical actions property owners can take for their ornamental landscape trees and should be used year-round.

Planting

■ Choosing the Tree – Choose trees that are healthy and have good structure. If a tree is lightly infested with adelgids, it’s still OK because you’ll treat it as part of the planting process. Don't bring saplings from infested areas onto your property.

■ Size – The planting size of a containerized or balled-and-burlapped hemlock is limited only by the space available and your ability to lift the weight and dig an adequate hole. It is generally not recommended to try to plant a hemlock that is more than about 5-6 feet tall because of the size of dirt ball needed for the tree to survive.

■ Timing – The best time to plant a hemlock is early fall when the soil temperature is still warm enough to encourage root development but the air temperature is cooling down. Second best is late winter / early spring before the flush of new growth.

■ Choosing the Planting Site – Hemlocks can tolerate full sun if they have an adequate amount of moisture, but they prefer semi-shade or at least afternoon shade in a moist but well-drained (not soggy) location. The best setting is on a north- or east-facing slope, in a ravine, or near a stream.

1. Check for drainage patterns that would cause excessive dryness or soggy conditions. Avoid such areas if possible.

2. Note the texture and structure of the soil. Loamy soil or amended clay soil is best. Avoid sandy or pebbly soil.

3. Eastern hemlocks require a pH range of 4.2 to 5.7. The soil in a woodland setting is normally acidic enough, but in a residential setting it may or may not be within the desired range. If you are in doubt about the pH of your planting site, contact your local Cooperative Extension Service agent about a soil test. If your soil is more alkaline than it should be, your Agent can provide instructions for amending it.

4. If the goal is to have full, fluffy trees with branches to the ground, space them 15-20 feet apart in a fairly sunny location. Hedge trees can be planted 3-4 feet apart.

Please see the Resources page, "Other SGH Instructions" section for additional details about planting various kinds of hemlock saplings.

Care & Maintenance

■ Water – Hemlocks are particularly sensitive to drought and do best with about an inch of water a week. Water newly planted ones once a week for their first year during any week that you don't have about an inch of rain. Established trees generally don't need weekly watering except during prolonged periods of drought. Click here for a Water Needs Chart showing how much water trees of different sizes need -- you'll be surprised!

■ Mulch – Keeping ornamental hemlocks mulched helps to conserve moisture for the roots, maintain more stable soil temperature, and reduce competition from weeds. Mulch made from shredded bark or hardwood is more effective and longer lasting than pine straw or nuggets. It should be applied about 3 inches thick from the trunk out to the drip line but pulled back from the trunk a couple of inches so as not to introduce fungal growth or other insect infestation. Don't make a mulch volcano.

■ Soil conditions – Avoid over-watering, soil compaction, or back-filling over the root zone. Re-check the pH of the soil in the root zone periodically and make any adjustment need to get it back into optimal range. If your hemlocks are in or bordering a lawn setting, be sure not to spread lime anywhere near them. You can give a light application of an acid-balanced fertilizer and Ironite during the second and third fall after planting; thereafter, established trees generally don't need these applications.

■ HWA – Plan to keep your hemlocks on a 5-year treatment cycle. But keep a watchful eye on them and be prepared to take action if there are sign of adelgids sooner. If you don't intend to use chemical treatment on infested trees, it's best to remove them so as not to maintain a banquet for adelgids that may be present. Alternatively, you can try to remove some of the adelgids mechanically by picking them off, pruning the infested branches, or using a high-pressure water hose. Don't fertilize infested trees until you have the HWA infestation under control (6-12 months) as this would encourage tender new growth which adelgids thrive on. Don't place bird feeders or deer feeders near hemlock trees; birds and deer can spread HWA eggs and crawlers for long distances. And if you go hiking, camping, fishing, etc. in an infested area (which includes most of north Georgia), your gear and clothes may be carrying adelgid eggs or crawlers, so take care not to spread them to your own trees.

■ Normal "forest management" – Consider thinning your hemlocks so the best ones have a better chance to survive. This means cutting any that are growing where you don't want them, growing too close to each other (unless you're using them for a hedge), that are physically damaged or dead, or that you don't intend to treat. It is not necessary to burn, chip, shred, or haul away the cut trees; when the tree is cut, the sap dries up and any adelgids that may be feeding on the tree will die.

■ Remember – Adelgids aren't the only pest attacking the hemlocks, so be on the lookout for other insect and fungal pests.

Please see the Resources page, "Other SGH Instructions" section for additional details about digging saplings, potting, maintaining a sapling nursery, transplanting, care and maintenance, and pruning.

Advantages of Cultural Practices

Cultural practices are usually easy enough for most property owners to do, involve very little expense, and require only some time and effort. They are an "all natural" approach that can help your hemlocks in their struggle to survive.

Disadvantages of Cultural Practices

Cultural practices alone will not eradicate the adelgids once they arrive on your property. They provide no long-term protection, and property owners should use them in combination with chemical treatment.

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