Fall Leaf Season and Clogged Gutters: A Local Tree Calendar
Every gutter company in America publishes a "fall leaf season" post, and most of them don't apply here. San Antonio's trees don't do fall the way Ohio's do. Our worst clogging season is March and April, when the live oaks drop, and our fall is a lighter second act that runs late into December. If you clean gutters twice a year on the northern calendar, you'll be up the ladder at the wrong times, and clogged gutters in San Antonio are mostly a spring problem. Here's the local version.
The trees that fill San Antonio gutters
Live oak. The big one. Live oaks are evergreen in the sense that they're never bare, but they replace their leaves all at once in March and early April, and a mature tree over a roof will fill a gutter in three weeks. The leaves are small, about two inches, and slip through any screen with wide holes. Then, right behind the leaves, come the catkins — the stringy yellow pollen tassels — which mat into a felt that holds water. Under the live oaks in Alamo Heights, Olmos Park and the older streets of Castle Hills, this is the season that matters.
Cedar elm. The most common native shade tree on the north side and in the newer subdivisions. It drops small, rough leaves in November and into December, and it's the main reason there's a fall cleaning at all. Light enough that a screen guard handles it.
Pecan. Along the creeks — Salado, Olmos, Leon, Cibolo — and in the old neighborhoods. Big compound leaves and husks from October through December. Heavy, but a basic screen keeps them out.
Hackberry. Everywhere, especially on lots nobody planned. Drops leaves in late fall and berries that birds carry onto roofs. A minor clog on its own; adds to the pile.
Ashe juniper (mountain cedar). Doesn't shed into gutters. In January it dusts everything yellow with pollen, which washes off in the first rain. Nothing to do.
Crape myrtle. Blossoms in July and August that get through almost every guard. Small volume, annoying.
The calendar
| When | What's falling | What to do |
|---|---|---|
| March – April | Live oak leaves, then catkins | The main cleaning: late April or early May |
| May | Storm debris, seed pods | Check downspouts after the first big storm |
| July – August | Crape myrtle blossoms | Nothing, unless a downspout catches |
| October – December | Pecan, cedar elm, hackberry | Second cleaning: December, after the cedar elms finish |
| January | Cedar pollen | Nothing |
If you have no big trees, the fall visit can usually be skipped and the spring one kept. If you're under a big live oak, the spring one isn't optional and a third look after the fall storms isn't unusual.
Why the fall storms make this worse
The pecan and cedar elm drop overlaps with the September and October storm season. A gutter that's half full of cedar elm leaves has half its capacity, and a plugged downspout outlet has none. October overflow is as often a clog at the outlet as a sizing problem, and the difference is easy to tell: a downspout that barely runs while the gutter above it spills is plugged. Flush it from the top. If the gutter's clean and still overflowing, read why gutters overflow in San Antonio rain instead.
What a fall cleaning actually involves here
Less scooping and more flushing. By December the cedar elm leaves are dry and light and come out in handfuls; the trouble is the outlets, where a season of small debris has built a plug at the top of each downspout. A proper gutter cleaning runs a hose down every downspout and watches the bottom, resets the extensions the mower kicked off, and looks at the corners while the ladder's up. Single-story homes typically run $120–$200; two-story $180–$300.
Guards, by tree
- Under live oaks: sloped stainless micro-mesh is the only type that handles both the small leaves and the catkins. Screens let the leaves in; reverse-curve hoods hold the catkins on top. Plan on one rinse from the ground in May.
- Under cedar elms and pecans: an aluminum screen at $5–$9 a foot does the job for a third of the price of mesh.
- Under nothing much: no guards. A $150 cleaning every other year beats a $1,500 install.
The gutter guards page has the full comparison, and honest numbers on how long each type takes to pay for itself.
Trimming
Limbs resting on the roof drop debris straight into the gutter with every wind. Cedar elm, pecan and hackberry can be trimmed any time. The Texas A&M Forest Service advises trimming live oaks only between July and January to avoid spreading oak wilt, and painting every cut right away; that's not a gutter rule, it's long-standing Texas oak advice, and losing a ninety-year-old oak in Alamo Heights to save a gutter cleaning is a bad trade. If a limb over the roof needs to come off a live oak, do it in the fall window, not the spring.
Signs of clogged gutters before the next rain
- Seedlings or grass sprouting along the gutter line.
- A dark tide line on the outside face of the gutter.
- Water spilling over the front in a light shower.
- A downspout that stays dry while the gutter above it runs over.
- A run that has sagged in the middle under the weight of wet leaves.
- Birds or wasps working the gutter line, which usually means there's something in it worth nesting in.
What a clog costs if it's left
A blocked gutter holds water against the fascia, and the board starts to soften within a season or two. The extra weight pulls hangers loose. Overflow lands at the foundation instead of at the end of an extension. And standing water in a warm gutter is a mosquito nursery by June. A cleaning runs $120–$300 here; a fascia board and a re-hang cost more, and foundation work far more.
Clearing a light load from the ground
On a single-story house with a light fall load, a telescoping wand on a garden hose, or a leaf blower with a gutter attachment, clears most of it without a ladder. Work from the downspout end back, so you're pushing debris away from the outlet. Then watch each downspout in the next rain to make sure it runs. Under a big live oak in April the load is usually too heavy for this, and a ladder clean-out is worth it.
Common mistakes
- Cleaning in November on a northern schedule and missing the April live oak drop.
- Blowing leaves off the roof into the gutter right after cleaning it. Do the roof first.
- Leaving the debris in the beds under the roofline, where the next rain washes it back toward the slab.
- Putting cheap wide-hole screens under live oaks.
Common questions
How do I know if a downspout is clogged?
Watch it in a rain. A clear downspout runs steadily from the bottom as soon as water reaches the outlet. A trickle, a gurgle, or water spilling from the gutter above it means a plug, usually at the top elbow.
Can clogged gutters cause leaks at the roof edge?
They can. Water backed up in a full gutter can wick under the first course of shingles or run behind the gutter and soak the fascia and soffit. It's one more reason to keep the outlets clear before the storms.
When is the best time to clean gutters under a live oak?
Late April or early May, once the leaves and catkins have finished falling. Clean too early and the gutter fills again within weeks; clean much later and the spring storms arrive to a full trough.
Do pecan husks damage gutters?
Not the metal, but they're heavy and they plug downspout outlets quickly. Under a big pecan, check the outlets after the fall drop even if the rest of the gutter looks clear.
Need gutter work in San Antonio?
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