Prevent Crabgrass Now

crabgrass in lawnCrabgrass weeds emerge from seeds present in the soil. They sprout when the weather first begins to warm in early spring. It only takes one seed to start a crabgrass infestation. If there is any in your neighborhood, you probably are going to get it too.

Seedlings sprout quickly, forming a clump with extensive roots where the soil is moist. Once established, it is difficult to weed out because of its roots at each node. These are called tillers because they, in turn, put down additional roots along their length and the process repeats exponentially. A single crabgrass plant’s root system can easily stretch nearly 4 feet in any direction. One plant will create a thick mat of both visible top and invisible root growth, which eventually smothers lawn grasses.

Growth is slow during spring months, by June the plants are producing their tiller roots and shoots; and flowering by late July and August. Once started, germination continues throughout the summer and into fall. Prior year crabgrass that did not die off from winter frosts may even produce new growth and a second crop of seed in spring or early summer.

Once infested, the important thing is to control the weed before it sets seed or you will have tens of thousands more seeds that can remain a threat for up to 3 years. The next spring they will sprout, and the vicious cycle begins again.

In short, crabgrass seeds from up to 3 years earlier are probably sitting in your lawn even as you read this, just waiting to infest your lawn all summer long. Once the soil temperature (not air temperature) reaches the 50-to-55 range for at least 7 to 10 days in a row, their seed dormancy will end, and they will germinate for up to six weeks.

Because crabgrass loves hot sun-baked open spaces and has tremendous growth, survival, and reproductive capabilities it is especially hard to fight here in our Valley. To succeed you must seek it out, not only in your lawn; but also in adjacent places such as cracks in sidewalks or along the edges of a driveway, etc. This will involve mulching, hoeing, and pulling when the plants are young and before they seed. If this all sounds like a lot of work – it is! Prevention Is Better Than a Cure.

Prevention Is Better Than Cure

Prevention is faster, cheaper and easier than a cure, and timing is everything. Your first and best line of defense is to stop the crabgrass seeds BEFORE they sprout.

You can do some of this by mulching. However, be careful – mulch that has lain undisturbed in the soil for a while can provide an adequate growth medium for weeds. Move the mulch about periodically with a rake to stop weed seedlings from germinating.

In most cases, mulching alone will not do the job and should be supplemented by pre-emergent weed control. But there is a very narrow window for applying a weed preventer because pre-emergent herbicides must be applied one to two weeks before crabgrass germination, which will occur here in our Valley within the next few weeks – so NOW is the time to move on this.

Alden Lane Nursery recommends Bonide Crabgrass Preventer with Fertilizer – A granular lawn fertilizer containing a premium pre-emergent weed killer which controls Crabgrass, Foxtail, Goosegrass, Poa annua and other annual grasses in established turf lawns and landscapes.

January Garden Checklist

checkbox Brighten the garden with colorful bedding plants. Refresh your garden beds and containers with primroses, pansies, Iceland poppies and more. Check with the staff for helpful advice and ideas.

checkbox Feed camellias, azaleas, rhododendrons monthly with Master Bloom through March.

checkbox Prevent crabgrass before it starts. Apply Bonide Crabgrass & Weed Preventer (with fertilizer) now to keep crabgrass seeds from sprouting in your lawn. Apply Bonide Crabgrass & Weed Preventer (without fertilizer) to ornamental landscape. Use Corn Gluten around edibles.

checkbox Spray Your Roses Now. An application of dormant oil just after winter pruning will help reduce pest populations by smothering over-wintering eggs. Spraying copper fungicides, as well, will halt diseases such as rust, blackspot and powdery mildew. Bonide All Seasons Spray Oil and copper are listed for use on organic gardens.

checkbox Protect tender plants when frosts are expected. If it hasn’t been raining, make sure to water plants ahead of a cold snap. Cover with drawstring frost bags or drape with protective frost blanket. String non-LED Christmas tree lights on your frost-tender plants when a freeze is expected. The warmth from the bulbs will provide another measure of protection.

checkbox Keep up your New Year’s Resolution . . . join the Livermore-Amador Valley Garden Club (lavgc.org) and the Mt. Diablo Rose Society (mtdiablorosesociety.org), Northern California Daffodil Society (daffodil.org), Iris Society (MtDiabloIris@gmail.com) and Valley Bonsai Society (valleybonsaisociety.com).

Prevent Oxalis and Winter-Sprouting Weeds

Apply pre-emergent weed control to prevent winter and spring’s tougher weeds including oxalis – the yellow-flowered clover look-alike. Many weeds begin to sprout as the weather cools, and fall rains begin. Thousands of the microscopic seeds have dispersed themselves after the spring and summer flower season. These seeds are poised to sprout as soon as the weather cools and rains begin.

With the weather cooling and rain arriving, oxalis, annual bluegrass, and many other weeds will begin to wake up in your lawn and landscape.  

If you have or have had oxalis (small clover-like leaves with a yellow flower pictured below), your lawn or landscape bed has already been seeded for next year’s crop. Thousands of the microscopic seeds have dispersed themselves after the spring and summer flower season. These seeds are poised to sprout now as soon as the weather cools and rains begin.

Pre-emergent weed control products prevent these new seeds from sprouting if timed correctly. Applying Bonide Crabgrass and Weed Preventer in fall will prevent weed seeds that typically sprout with the first fall rains. Using now prevents oxalis and annual bluegrass and helps break the life cycle of the weed, bringing it into control.

Caution! Pre-Emergents will also prevent lawn seeds from sprouting. Postpone your weed prevention if you plan to reseed a lawn in the next couple of months.

Irrigation Checkup Time

With warmer weather upon us, it’s time to give your irrigation systems a seasonal look-through to confirm everything is in working order. We don’t want to waste water.

Bugs can plug nozzles; heads can shift out of alignment, calcium can accumulate and reduce flow. Turning everything on during daylight hours will let you see what’s working and what’s not.  The following charts can help with a thorough checkup.

Periodic Checklist

Task Annually Seasonally Monthly Notes
Change Batteries X Check connections for corrosion and battery leakage damage. Make sure transformers are working. Check for frayed or broken control wires. Verify fuses, circuit breakers, etc. are OK, and the electrical supply circuit is functional.
Flush System X Remove line end caps and run water until clear.
Clean Filters X Clean screens. Replace filter elements and broken or torn filter screens.
Adjust Timer Settings X Adjust for changes in rain. Be sure to avoid zone time overlaps that will affect performance due to low pressure. Watering early in the morning saves water due to lower wind dispersal and reduced evaporation.
Visual Inspection Test X See monthly checklist below.

Monthly Checklist

Monthly Checklist
Monthly test run each valve during daylight hours and perform a visual
inspection
Checkpoint Yes No Notes
Is any water being sprayed on the street or sidewalk? We must conserve every drop.
Is there run-off of water? Some surfaces absorb less water than others. Sloping areas often need less water per time and more frequent watering to prevent run-off. Note: our hard clay-type soils may need a periodic application of Grow More EZ-Wet and Gypsum to solve chronic water run-off problems.
Are there excessively damp areas or standing water ? Shaded areas, hard clay-type soils, lower levels receiving run-off often need less water. Note: our hard clay-type soils may need a periodic application of Grow More EZ-Wet and Gypsum to solve chronic water run-off problems.
Are there obstructions preventing the water from reaching the
desired areas?
Be aware that changes in plant size and position or the addition or alteration of landscape items may require sprinkler adjustments.
Are there any observable leaks or breaks in the pipe?
Are any heads/emitters missing?
Do you need fewer or additional active heads/emitters? Be aware of changing needs due to changing landscapes. Sprinkler systems should be considered a seasonal work in progress rather than static.

Sometimes adding/activating or disabling heads/emitters will accomplish more than trying to adjust a single head/emitter.

Are any heads/emitters broken? If you have pop-ups make sure, they rise and retract fully.
Are any heads/emitters clogged?
Are any heads/emitters pushed too far into the ground?
Are any heads/emitters tilted/spraying in the wrong direction?
Is the pressure too low? Spray not reaching all desired areas. Spray forming large water droplets. Presence of doughnut-shaped dry areas. Rotor speed is too slow, and rotors are not rotating. See timer zone overlap note above. Note: choose a time in the
morning when competition for water is at a minimum — in other words, avoid
shower time.
Is the pressure too
high?
Spray overshooting desired areas. Spray misting. Dry areas between heads. Rotor
speed is too fast, and rotors are not rotating. Heads/emitters/supply lines are leaking.
Is the timer working properly? Confirm program settings are proper for the current season.