Mountain cedar, which is really Ashe juniper, drops heavy pollen from roughly mid-December through February, peaking around mid-January. The best time to wash your house is after the peak, in the spring window from about mid-April into May, not during the pollen drop.
What cedar pollen does to your exterior
Cedar pollen is fine and powdery, and it sticks to everything. It leaves a yellow-green film on siding, brick and windows. It settles into gutters and downspouts, where it mixes with oak leaves and other debris. It stains concrete and pavers a dull yellow-brown. And it is sticky enough that a garden hose will not rinse it off. A proper wash with the right cleaner is what lifts it. The film is most visible on dark surfaces and on the north side of the house, where it stays damp longest.
Why it is heaviest west of I-35
Ashe juniper grows densely in the Texas Hill Country west of I-35, and the pollen blows for miles on dry, windy days. Cedar Park, Georgetown, Round Rock and the other towns on the west side of the interstate get the heaviest coating. The pollen is so concentrated that it can affect people who do not usually have allergies. One tree can release billions of pollen grains, and when the cones open on a cold, dry, windy day, the pollen billows off the tree like smoke.
Washing during the drop usually does not last
If you wash in the middle of cedar season, a fresh coat of pollen lands on the house within days. The film comes back, and the wash is wasted. Unless you are selling the house or hosting an event, it is usually better to wait until the peak has passed. The pollen is airborne and blows for miles, so removing juniper trees from your property does not solve the problem.
The spring window
Once the heaviest oak pollen is behind us, from about mid-April into May, the spring window opens. Temperatures are still mild, the pollen load drops, and a wash done now stays clean through the summer. This is the best time to book a house wash, a driveway cleaning and a gutter clearing in one visit. The mild temperatures also mean the cleaning solution has time to dwell before it dries, which gives a better result.
Gutters after the drop
Cedar pollen mixes with oak catkins and other debris in the gutters during winter. By spring, that mix can be thick enough to block downspouts. Clearing gutters after the pollen and seed drop, and again after the leaves in fall, keeps water flowing where it should and away from the foundation. A clogged gutter overflows and dumps water right beside the foundation, which is exactly what Central Texas clay soil does not need. Gutter cleaning pairs well with a house wash, since both are done from the outside in one visit.
A simple spring exterior plan
- House wash: once a year, in the spring window or early fall
- Driveways and concrete: any dry stretch, best when it will not rain for a day
- Gutters: late spring after pollen and seed drop, and late fall after leaves
- Fences and decks: clean and let them dry fully, then stain on a dry, mild stretch
Timing a wash to the pollen calendar is the difference between one clean spring and washing the same walls twice. Send a photo of the north wall and the gutters and we will suggest a week to book.
Common questions
When does cedar pollen season start in Central Texas?
When is the best time to wash my house after cedar pollen?
Does cedar pollen stain concrete?
Related: House washing service, Gutter cleaning service, Best time of year to pressure wash
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