Thursday, May 14, 2009

Garden Checklist

From the Fresno Bee, May 14:

Tasks
: check drip and sprinkler systems for clogs and leaks.

Pruning
: remove spent lilac flower clusters just above points where leaf buds are forming.

Fertilizing: almond, apple, cherry and plum trees.

Planting: blue marguerite (Felicia), gazania, hemerocallis; dahlia; cucumber, eggplant, okra, parsley; hydrangea; impatiens from seed.

Things to ponder: This is the month to propagate geraniums and other soft wood perennials from cuttings. [Geraniums are easy---just break a stem off, and put it in the ground (or pot) with a few inches below- and a few inches above-ground level. It will root and thrive!].

. . . . .

"Consider Salt in Water When Leaves Yellow"---Elinor Teague

In the spring plants should be green with new growth. Plants that are under stress from cultural conditions, nutrient deficiency or poor soil conditions will begin to show "stunted growth, branch and twig dieback, and yellow leaves."

Over- or under-watering are cultural conditions that can cause problems. Iron chlorosis, which can cause yellow leaves, is most often caused by over-watering. This "interferes with the plant's ability to draw up iron from the soil." Iron chelated products won't help until the water situation is fixed. "In general, landscape plants, flowers and vegetables should be watered deeply when the top inch or two of soil has dried out. Larger trees and bushes need watering when the top three to four inches of soil is dry."

When plants absorb nutrients from the soil, they also draw up water, which leads to a build-up of salts on the soil surface. If your acid-loving plants are showing signs of yellow leaves and branch die-back, "let the hose drip slowly for a day or two several times a year, thoroughly irrigating the soil." The salts will be washed down below the root zone.

A crusty film on top of the soil is another indication of salt build-up. Mulching will help slow soil moisture evaporation, therefore slowing the build-up of salts.

High alkaline or pH levels will also affect the health of plants, and adding more iron and other minerals may not help. Lowering the pH level can be done by applying sulfur at the root zone, and may need to be repeated.

[For vegetables, soil pH should be close to neutral or 7 on the pH scale of 1-14. Below 7 indicates acidity, and above 7 indicates alkalinity. There are soil kits that can be purchased at the store, or a soil sample can be taken to the county extension office for them to test. Some plants, like azaleas, camellias, hydrangeas, gardenias and blueberries, thrive in acid soil and will die in alkaline soils. Although they do like acid soils, they do not like salt buildup].

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