MAINTENANCE THIS MONTH- April
 
Key words for April are "weed", "feed" and "mulch". Now's the time to feed plants with your fertilizer of choice and topdress beds with a couple inches of compost (work into soil when planting annuals, perennials and shrubs, but not landscape trees). Finish off with 2-4 inches of bark (micro, mini, med. or large). Pull young weeds early in the month while they're young and soil is still relatively moist.

LAWN MAINTENANCE: Feed your lawn with a high-nitrogen lawn food. Aerate and overseed thin patches, if necessary. Get out the mower...

UC GUIDE TO HEALTHY LAWNS: Want to know what type of lawn you have and how to maintain it? Want to put in a new lawn or renovate an old one? Need lawn pest info? The new UC Guide to Healthy Lawns is an excellent resource. So is the UC "Lawn Watering Guide for California".

SHADE TREES: Having any tree concerns? Call a certified arborist for help.

BACKYARD ORCHARD TREES, SHRUBS & VINES:

Citrus are heavy nitrogen-feeders. An application of nitrogen in late winter/early spring will provide adequate nutrients for flower and fruit set.

RECOMMENDED FERTILIZER APPLICATION RATES:

NITROGEN (N): regular application required
1 to 2 year old tree: 2 tablespoons nitrogen fertilizer 3 to 4 times per year or 1/10 lb. nitrogen fertilizer per year
3-year-old tree: 1/4 lb. nitrogen applied to dripline before watering
 4+ year old tree: 1 lb. actual nitrogen per tree per year. So, if your nitrogen fertilizer contains 33% actual nitrogen (33-0-0), you will need to apply 3 lbs. Some references recommend dividing applications into thirds, totaling 3 applications per year (early spring, summer and fall). If you follow that recommendation, make sure you avoid feeding oranges and grapefruit during summer to avoid thick rinds, lower juice content and re-greening of Valencia oranges.
PHOSPHORUS (P): 1 lb. phosphate per tree every 3 to 4 years per mature tree
POTASSIUM (K): as needed (deficiency: general leaf pattern begins as a yellowing of the tips and margins, which then gets broader. Necrotic areas and spotting can develop on the leaves) 2.5 to 5 lbs. potassium per mature tree per year for 2 years if deficiency is noted.
MAGNESIUM (Mg): as needed (deficiency noted by yellowing between veins of older leaves followed by dropping.)
ZINC: as needed (deficiency symptom is "mottle-leaf", exhibited by "small terminal leaves with mottling between large leaf veins". Apply late-winter or early spring foliar spray (carefully follow label directions)
IRON: as needed (deficiency symptom is yellowing between large leaf veins... i.e. interveinal chlorosis)
foliar spray (follow label directions)
MANGANESE (Mn): as needed (deficiency: young leaves turn light green between veins, often more noticeable on tree's north side).

Combination "micronutrient sprays" are available at your local nursery if you suspect multiple deficiencies. A specialized citrus fertilizer or "citrus food" likely contains all necessary macro- and micro-nutrients.

References: California Master Gardener Handbook and the following books:
 
  LanceWalheim.com...
This guy literally wrote the book on citrus!		    
CAMELLIAS, AZALEAS & RHODODENDRONS: Feed your plants with "azalea/camellia food" after bloom. Prune right after bloom to shape and control size.
SPRING-BLOOMING SHRUBS: Prune early-spring bloomers like spiraea, quince, forsythia and lilac after they flower.
BULBS: Leave the foliage on spent spring-blooming bulbs. Those leaves manufacture food for next years flower.
HYDRANGEAS: Buds are forming now. Want to "blue up" your hydrangeas? Hydrangeas! Hydrangeas! (my favorite hydrangea website) tells you how... http://www.hydrangeashydrangeas.com/colorchange.html
BOUGAINVILLEA: Prune bougainvillea as soon as danger of frost has passed. It blooms on new wood.

IRRIGATION: It's probably time to start watering again. Adjust your irrigation controller for a spring watering schedule.

Now is a good time to check your drip system for problems. If you're like me, you've managed to chop many of those long tubes into penne pasta-sized bits... It's also a good time to flush out sediment, earwigs, etc.

ANNUALS: Continue deadheading cool-season annuals (pansies, primroses, etc.), but don't buy any new ones. It's time to shift into "summer color" gear.

PERENNIALS: Feed established perennials to get them off to a good spring start. Feed newly-planted perennials with starter fertilizer (lower N, higher P) or controlled-release fertilizer like Osmocote.

Now's a good time to root cuttings from your mums, carnations, geraniums and succulents like orchid cactus.
ROSES: Feed roses with a complete fertilizer this month. Watch for aphids. When you see 'em, blast 'em off with a hose. Prune non-repeat bloomers after blooms fade.

WEEDS: What's the saying? Weed now, or forever hold your weeds (or something like that)... See the UC Weed Gallery for proper identification and the UC IPM Pest Notes for how to manage them.

PESTS: Slugs, snails and aphids, oh my!.Visit the fabulous UC IPM website for control measures. Here are a few timely links to pest pages:

Slugs & Snails: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7427.html
Aphids: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7404.html
Mosquitoes: Eliminate bodies of stagnant water where possible and use mosquito dunks where not. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7451.html
Ants: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7411.html
Earwigs: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74102.html

Want to see what the GOOD GUYS look like?

WE ALL KNOW COMPOST HAPPENS... but is it happening in your yard? Check out Project Compost!