Oak habitat is in decline
Oregon white oak trees (Quercus garryana) provide a key habitat in Washington County. Oak trees are known as a tolerant species that can survive droughts and resist fire and they support dozens of rare birds and wildlife species. Tualatin SWCD is working to protect this unique and threatened habitat.
You can help by planting an oak tree
Majestic, unique, strong, resilient. There are so many reasons we love oak trees. Each oak tree provides habitat, food, shelter and shade for wildlife and people. And we see fewer and fewer each year. In Washington County there are plenty of open areas that would benefit from an oak tree. As is the saying, the best time to plant a tree is 20 years ago!
Oregon white oak grow slowly. Give them extra care when you first plant them and you’ll be rewarded with a large, graceful tree that makes a big difference for wildlife across our watershed.
Where to buy
You can find Oregon white oak trees (Quercus garryana) at many local nurseries in Washington County. Oregon white oak are fairly distinct from other oak trees with their rounded leaf lobes. We recommend going to a native plant nursery where you may be less likely to find English oak (Quercus robur) which is a species that could be mistaken for Oregon white oak.
Visit our friends at Backyard Habitat Certification Program for a great interactive website that can point you to available plant nurseries in the area.
You can also grow your own oak tree from acorns! We will share more about how to do that below.
Choose your location thoughtfully
When planting, think about 100 years from now. How will a tree that can be 100 feet tall and just as wide fit into the space.
- Pick a sunny location, oaks do best with full exposure
- Give the tree 40-50 feet of space at least away from other trees and buildings
- In the Willamette Valley most oak are found in lower elevations, below 2000 ft is a safe bet
- If you plant a bigger tree (3+ ft) you will need to water the tree the first summer or two to help it establish
- Plant in an open area away from prolific weeds (such as Himalayan blackberry and Reed canary grass)
- Don’t plant directly in standing water, oak can tolerate wet soils but we don’t recommend planting directly into a wetland
Planting and caring for your tree
Essential supplies: oak seedling & shovel.
Additional supplies: mulch & seedling protector tubes.
Plant your tree in the fall and winter when soils are wet and cold, between November and February. This timing allows for the roots to establish before the growing season. Plant into a hole as deep as the pot and plant the tree collar at the level of the soil (at the point where the roots join the stem). Fill in the hole with soil and push down the soil as you go to reduce the air pockets in the hole.
Spread mulch (bark chips or leaf litter) 2 inches thick around the base of the tree. Weed around the base annually until the tree has a chance to grow taller than the surrounding weeds.
If you have wildlife like beaver and deer in the area, it’s a good idea to add a cage or tube around the tree for protection for the first few years. Search for “seedling protectors” from forest supply companies online.
Keep an eye on your tree, weed and water as necessary. Smaller trees with healthy root systems (full of small fibrous roots) can survive without watering. Counterintuitively, large trees may need more watering during the hottest weeks of summer in the first two years in order to support their larger root system.
Starting an oak from an acorn
Essential supplies: oak acorn, pot, bucket to float the acorn, potting soil & caging/protection.
There’s no cheaper and more fulfilling way to plant an oak tree than to start one from an acorn.
Collection: Gather your acorns between September through November directly from an Oregon white oak tree. Make sure you’re collecting from a healthy and happy looking Oregon white oak tree (look for the round lobed leaves and round tree canopy).
Checking health: Once you’ve gathered your acorns remove those that have holes, a sign of insect damage. You can put the acorns in a bucket or jar of water overnight. The acorns that float are probably damage and you can toss. Those that sink are ready for germination.
Potting: You can plant your acorns immediately after soaking them. Place them in a long treepot or 1 gal bucket. Fill your pot with an even mixture of outdoor soil (ideally from under an oak tree) and potting soil. Put the acorn sideways, 1/4 inch below the level of the soil. Cover with wire mesh or some form of breathable protection to keep critters away. You can expect a sprout to form in the spring. Keep the sprout protected and potted for a year or two, watering regularly in the summer.
Planting: After the seedling is two years old it’s big enough to plant outside. Look to our tree planting guidelines above for tips.
Storing: If you’re not ready to plant your acorns right away, dry them off and stick them in a fridge until you’re ready to plant. It’s best to plant within the same growth year (i.e. acorns collected in November should be planted before the following summer).