Thank you for sending in pics of your Oregon Green Pine. In the last photo, there appears to be a fuzziness at the base of the new growth. Is there a fuzzy webbing on the actual tree?

Kate

DC Master Gardener

Hi Yvette, 

Drooping is sometimes a response to stress from heat and humidity. DC is at the very limit of Austrian Pines which will grow in zones 3b-7, but do better in colder areas of their range. You have probably caught it in time, plus you have been keeping it from drying out. https://naturalresources.extension.iastate.edu/forestry/iowa_trees/trees/austrian_pine.html#:~:text=Hardiness%3A%20Zones%203b%20through%207,Grows%20best%20in%20colder%20climates.&text=Mature%20Shape%3A%20Densely%20pyramidal%20when%20young.

Austrian Pines are beautiful trees, but can be challenging to grow due to their susceptibility to many pests and diseases. Here is a checklist to help it withstand stress, many of which you may already be doing, or have done.

1. Needs well-drained soil, adaptable to sand, clay, loam, but well-drained. Does well in moist (well drained) soil, but can handle some drought when well established.

2. Generally grown in full sun, but since DC is at the very warmest edge of its range, morning sun and afternoon shade would likely work better. Only 2 hours/day seems less than ideal, but wouldn’t recommend moving trees in summer, especially if stressed. And may prove manageable given our ever hotter summers.

3. Water at the treeline, as needed, keeping the tree dry, enough to receive about 2” rainfall over the course of the week. (A tuna/cat food can near the tree is a handy 1” rain gauge, empty when full). Or roughly, 25 gallons of water per small tree  over the course of the week total, including rainfall.

4. Leaving a gap around the trunk, mulch the tree with organic mulch like arborist wood chips, chopped leaves, etc.

5. Do not fertilize unless a soil test shows a deficiency, and don’t fertilize a stressed tree. If you haven’t done a soil test in the past 5 years, it would be a good idea.

6. Check for pests, disease. At the base of the tender new growth is a prime spot targeted by sawfly & more.

White resin is typically present on Austrian Pines and is normal. However, a symptom of Cytospora canker is oozing resin. Cytospora is a common fungal disease & onset is often triggered by stress. So please check the whitish areas & new growth and feel free to reach out.

Potential pests include: aphids, adelgids, bark beetle bore, sawfly larvae caterpillars, sawflies, pine needle miner larvae, pine needle scale, pine spittlebugs, spruce mites, pine moth, and pine wilt nematode.

https://naturalresources.extension.iastate.edu/forestry/iowa_trees/trees/austrian_pine.html#:~:text=Hardiness%3A%20Zones%203b%20through%207,Grows%20best%20in%20colder%20climates.&text=Mature%20Shape%3A%20Densely%20pyramidal%20when%20young.

Oregon State University has Pinus nigra ‘Oregon Green’ in their collection. Looks like it will be a bit smaller than the species which is nice for a city garden. Maybe it has improved disease resistance & other qualities to boot! They credit the development of this cultivar to Van Meter Nursery in Oregon. https://landscapeplants.oregonstate.edu/plants/pinus-nigra-oregon-green

In researching Austrian Pines, the contrast between nursery trade descriptions as an easy to grow tree with state university descriptions as a beautiful tree with unfortunate susceptibilities became apparent. But it is a beautiful tree & we love trees and helping DC residents, so please keep us posted!

Kate

DC Master Gardener

Oh good. Thanks for checking, wanted to make sure it was just resin and not adelgids!  Glad we can help. I am actually one of the volunteers on UDC’s new extension site, launched with UMD help!

Hope you will keep up posted!

Kate McLynn, DC Master Gardener

Wonderful! I look forward to it!

Kate 

DC Master Gardener