The buzz of lawnmowers has become a familiar sound at the start of this spring. If your lawn is anything like mine, it's growing like crazy with this warm then wet weather we have had.

You might not think there is much to mowing your lawn but proper mowing, combined with other lawn maintenance practices, is critical for attractive, well-groomed lawns. One of the biggest mistakes people make is mowing too short. The following was taken from the UC Guide to Healthy Lawns.

Optimum cutting height is determined by the growth habit of a particular grass and its leaf texture (i.e., the length and width of leaves). A grass's survival depends on its producing adequate leaf surface for food production through photosynthesis. Mowing too low removes too much of the grass's food producing area. As the grass literally starves, the lawn thins and looks poor. Conversely, mowing too high can hurt the appearance or usefulness of the turfed area.

No single mowing height is best for all turfgrasses; mowers must be set differently for each grass. The table below shows the ranges for optimum mowing heights for California lawns. Within its optimum mowing height range, each grass species will be healthier and have a deeper root system the higher the grass is mowed. Also, within its recommended mowing range, a grass that is cut higher is more tolerant of drought, heat, traffic, shade, disease, and pests than one that is cut lower.

As a general guide, follow the one-third rule: mow often enough so that no more than one-third of the length of the grass blades is removed at any one time. For example, if you maintain a turf-type tall fescue lawn at 2 inches, mow it when the grass height reaches 3 inches. This may mean mowing tall fescue once a week during the spring and every two weeks during the summer. The table also gives the height at which you need to mow your lawn in order to best maintain your desired lawn height. A lower-mowed lawn will require more frequent mowing than that same lawn would if mowed higher.

ADDITIONAL MOWING TIPS

• Do not mow wet grass: it sticks to mower blades and clogs the mower.
• Change the direction of mowing periodically to prevent a “washboard” effect.
• Sharpen lawnmower blades regularly. Dull mowers leave a ragged appearance from crushed or uncut grass blades, and damaged grass may be more susceptible to disease.
• Do not drastically or suddenly change the cutting height. If the grass has become too tall, re-establish the recommended height by mowing more frequently for a while and gradually lowering the mowing height of successive cuttings, following the one-third rule.
• Since mowing stresses the grass, do not mow a lawn under drought or other climatic stress conditions. Grass that is suffering from lack of water should be watered and allowed to dry before being mowed.
• Mow a shady lawn slightly higher and less frequently than is normally recommended for that grass species. Shade reduces photosynthesis, and slightly higher mowing heights allow more leaf surface that compensates for the lower light levels

Stay tuned for more posts related to healthy lawns. If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website.

Spring is when we run to the nursery, anxious to get started after oggling garden magazines all winter. Those six-pack annuals are so tempting and, fortunately, innocuous, but there are a few truly dangerous specimens lurking out there, waiting to take over your garden and then some!

Invasive species take advantage of conditions where their natural controls, such as pests and disease, are often absent. This allows them to grow like crazy, displacing native plants and the animals that depend on them, reducing the biodiversity essential for a healthy ecosystem.

Some invasives can be found in nurseries and are best avoided:
1. English Ivy is a familiar sight in urban and suburban gardens. This creeping vine forms “ivy deserts” where it outcomptes other plants for light and water. The thick, waxy foliage makes herbicides largely ineffective. Don't buy it; if you have it, consider having it removed.

2. Periwinkle spreads by rooting wherever it's stems touch the soil. It is especially dangerous in riparian areas where even a small piece can wash downstream and become established. Remove by pulling out all root nodes and stolons. Do not remove by mowing; the chopped-up pieces are likely to re-root.

3. Broom (Scotch, Bridal, French, Portuguese, Spanish) produces copious seed and biomass which is a fire hazard in some areas. The foliage is nutritionaly lacking and has little livestock value. Some cultivars are said to be “sterile”, but these claims have not been verified.

The California Invasive Plant Council has a list of top 15 invasive plants that are a concern in the Central Valley. Don't worry if some of your favorite plants are on the list; Cal IPC has substitutes as well!

If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website.

Ladybugs love aphids and torch lilies

There is something quite elegant and charming about little red-spotted lady bugs embellishing spring flowers. Make no mistake, however; lady beetles are an aphid's worst nightmare, sucking out their guts, leaving behind empty shells in their wake. Good for people, bad for aphids!

Here are more facts about and reasons we love lady beetles:
What they are: Often referred to as ladybugs, lady beetles are just that: beetles! About 40% of all insect species are classified as beetles; fortunately for humans only a few are considered garden pests.

Why we love them: Lady beetles dine primarily on aphids (and occasionally whiteflies) for free, making them the best pest control you can get.

How to attract them: Avoid pesticides, or try less toxic kinds, to avoid harming ladybeetles and other beneficial insects. Most healthy plants can handle a little aphid damage until the lady beetles arrive to eat them.
Garden centers sell ladybeetles, but there are a lot of variables between how well they were handled, how old they are, “operator error” when releasing, etc. For advice on proper handling of purchased lady beetles, visit the UC IPM webpage here.

How to keep them: Lady beetles generally migrate to the foothills for winter, but are more likely to overwinter in the valley if they have a nice, cozy place to stay and sources of pollen and nectar in the fall to fatten up newly emerged adults for winter hibernation. Good hibernation plants form large, dense, mounding clumps, such as Torch Lily (Kniphofia uvaria) and California native .
For pollen and nectar sources in the fall, try planting late bloomers such as California fuchsia (Epilobium canum) and plants with an extended or “second” bloom season such as  Foothill penstemon (Penstemon heterophyllus).

If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website.