Leaves, cottonwood cotton and needles on artificial turf: the tools and the timing

01Which tool should I use: blower, rake, broom, sweeper or vacuum?

A blower for dry debris, a plastic rake or broom for the rest. What the sources say about each:

Sources: Motz, FieldTurf Landscape, Synthetic Turf Council maintenance guidelines.

A few habits keep the infill where it belongs:

• Wait for dry. Motz says a blower may not suit leaves that a storm or heavy rain has clumped together; rake those, or let them dry first.
• Blow across the turf, not into it. Angle the air along the surface in long passes toward a bed, the patio or one corner, and bag the pile from there.
• Start where the wind piles it. Leaves and cotton collect against fences, walls and edges first.
• Watch the ends of your passes. If little drifts of sand or granules show up, brush them back across the area. If the infill looks thin in spots, see how often turf needs more infill.

Leaves that sat long enough to flatten the blades need a brushing too; that is in fixing matted artificial turf.

02What falls on Northern Colorado turf, and when?

Sources: Colorado Department of Agriculture, CSU Extension PlantTalk 1538, 1758, 1768 and 1760, USDA NRCS.

Cottonwood cotton. CSU Extension says female cottonwoods shed their cotton in June, often enough to turn nearby lawns white, and that the cotton carries the tree’s small seeds on the wind. The Colorado State Forest Service places plains cottonwood in floodplains and along streams. From that, our inference rather than anything mapped: yards near the Poudre, the Big Thompson, the St. Vrain and the South Platte, or near old cottonwoods on a ditch or in a park, should expect the heaviest June. Dry cotton is light debris; let it drift into a corner, then blow it into a pile and bag it.

Fall leaves. In the one full count of Fort Collins street trees we found, a 2003 USDA Forest Service analysis, green ash was the most common street tree at 22%, with honeylocust at 10.2%. The count is old, but the two species drop differently. USDA describes honeylocust leaves as small and doubly compound, so the pieces are small enough to settle between the blades, where a blower or broom reaches better than a rake. Plains cottonwood leaves run 3 to 6 inches long and sit on top, where a rake handles them.

Pine needles. CSU Extension says evergreens shed older needles regularly and that Front Range pines, spruces and firs often have a heavy drop. Ponderosa needles are stiff and 3 to 7 inches long. FieldTurf says needles left for long periods get trapped between the fibers; a low blower or stiff synthetic broom gets them out, and a plastic rake lifts buildup.

A dry spring can mean more seed. CSU Extension says a dry, windy Front Range March and April stresses trees, and that abnormally large seed crops, sometimes tied to a lack of moisture, are a normal response (PlantTalk 1759).

03What happens if the leaves stay on all winter?

They stop being a surface problem and become an infill problem:

• The Synthetic Turf Council says leaves and other debris left on the surface migrate into the system, inhibiting drainage and compacting the infill.
• FieldTurf says leaves left over winter can decompose into a layer of organic matter that impedes drainage and encourages moss.
• Motz says leaves and twigs can block the holes in the turf’s backing.

The council’s advice for sports fields is that leafy trees shouldn’t stand next to one at all, if possible. A yard doesn’t get that choice, so the answer is frequency. FieldTurf says to remove fall leaves regularly; Motz says a few times a year, especially in autumn. Under a big ash or cottonwood at peak drop, that can mean more than once a week. Get the last of them off before snow covers the yard, because anything under the snow sits there until it melts.

If the turf already puddles or shows a green film, the debris may have done its work.

04Why are tree seedlings sprouting in my turf?

Because seed landed in the infill and nothing stopped it. CSU Extension lists female ash, Siberian elm, honeylocust, hawthorn, crabapple, maple and goldenrain tree among the trees that seed themselves into lawns, and says dense grass mowed at 3 inches inhibits most seedlings. Synthetic turf has no living grass to crowd a seedling out and no mower to cut it back, so the job is yours.

Siberian elm is the one to know. The Colorado Department of Agriculture lists it as a List C noxious weed, a species so widespread in Colorado that statewide eradication is impractical (CDA noxious weed list). Its seed travels mostly on the wind, in samaras set in spring. The department’s fact sheet says the seed can germinate within a week or two in damp conditions and stay viable in the soil for up to eight years, and that very young seedlings pull fairly easily by hand, especially when the ground is moist.

On turf, that becomes a routine:

• Blow the samaras off in spring before a wet spell. Rain or a rinse gives them the damp start the fact sheet describes.
• Pull seedlings young, after a rain or a rinse. FieldTurf says seed-grown weeds in infill have shallow roots and usually come out by hand.
• Check edges and corners first. FieldTurf says airborne seed sprouts in the infill and around the edges, which is also where blown seed collects.
• Treat June cotton the same way. It carries cottonwood seed, so don’t leave drifts sitting in damp corners.

05Where do the leaves go once they’re off the turf?

Somewhere other than a pile on the turf, which is the same rotting layer described above. The options:

• Your own beds or compost. Motz suggests piling leaves into garden or landscape beds to break down. CSU Extension calls fall leaves a valuable resource for compost; whole leaves compost better than shredded ones, a tended bin can finish by late spring, and an unattended pile may take two to three years (PlantTalk 1612).
• Larimer County’s Green Waste Program. It takes grass and leaves as yard waste, grinds them and uses them on site. It won’t take bags, so plan to empty them at the drop-off, and it won’t take weeds, so pulled elm seedlings go in the trash. Loads are charged at the main gate, and a load mixed with trash goes to the landfill (Larimer County Solid Waste).
• Curbside and Weld County towns. It depends on your town and trash hauler: ask what yard-waste service they offer, what goes in it and when it runs.

In Fort Collins, the rest of what to know about turf in town is on our Fort Collins page. Planning a new lawn replacement under mature trees? Our artificial turf installation page covers the job.