- Author: Ed Perry
- Editor: Anne Schellman
To have your soil analyzed, contact a commercial testing laboratory. For a list of soil laboratories located in Stanislaus, Merced, Fresno, and Merced Counties, visit https://cemerced.ucanr.edu/ClimateSmartAg/HSP/SoilTest/Soil_Testing_Laboratories_in_Fresno_Madera_Merced_and_Stanislaus_Counties/
Vegetable Gardens
For vegetable gardens, the application of a fertilizer containing nitrogen and phosphorus is usually all your soil will need to get your vegetables off to a strong start. Other nutrients like zinc or iron are sometimes deficient or unavailable in certain soils, but they are usually not applied unless plant deficiency symptoms appear.
Diagnosing a Plant Problem
Besides moisture, oxygen is also required in the soil for good root growth. Poorly drained soils often have little oxygen in them because excess water fills all the spaces between the soil particles. My advice to gardeners is to correct drainage problems first, then worry about fertilizers. Often problems with sick and dying plants are caused by overwatering or a lack of good soil drainage than by nutrient deficiencies.
If you have an unhealthy plant, gently dig near the root system and check soil moisture and drainage. Since plant roots need oxygen, roots may suffocate if excess water does not drain quickly. Unfavorable climatic conditions, including temperature extremes and drying winds can also affect plant growth, as well as insect pests and diseases. For small plants, pull up a plant or two and check to see if the roots are healthy.
The best way to keep soil healthy, especially in vegetable gardens is to add compost annually to improve soil health. For perennial crops like fruit trees, annual applications of fruit tree fertilizer in spring can be beneficial.
The UCCE Stanislaus County Master Gardeners Can Help!
If you need help diagnosing a plant problem, take a plant sample to the UCCE office located at 3800 Cornucopia Way Ste A in Modesto. Master Gardeners are available on Wednesdays from 9:00 a.m. to noon in person or by phone (209) 525-6802. You can drop off a sample anytime during business hours or fill out an online survey and attach photos using this link http://ucanr.edu/ask/ucmgstanislaus A Master Gardener will get back to you within 5 days of your request.
If you live in another county in California, you can find your local Master Gardener program by using this link https://mg.ucanr.edu/FindUs/
Ed Perry is the emeritus Environmental Horticultural Advisor for University of California Cooperative Extension (UCCE) in Stanislaus County where he worked for over 30 years.
/h4>/h4>/h4>- Author: Ed Perry
Soluble salts are naturally occurring minerals, such as sodium, chloride, boron, calcium, and magnesium, that are dissolved in water. Some of the water in Stanislaus County has relatively high levels of certain salts, but in general, all water has some salt. Fertilizer dissolved in water also turns into a soluble salt. After water evaporates from the potting soil, the salts stay behind. Eventually, an excessive amount of salt may be absorbed by the roots, move upward in the plant, and concentrate in the leaves, causing tip burn. As salts in the soil become more concentrated, plants find it harder and harder to take up water. If enough salt accumulates in the soil, the water absorbing root tips are killed, and the plant begins to wilt and drop leaves.
To combat this problem, be sure you water correctly. Water plants enough so that some water moves through the soil and out the pot's drain hole. Then empty the drip plate. Do not allow the pot to sit in water. If drained water is reabsorbed by the soil, the salts that were washed away are taken back into the soil. The process of removing soil salts is called “leaching.”
It's a good idea to leach your house plants every two or three months. To do this, water the soil thoroughly, as you usually would. Then, after about five minutes, water again, letting excess water flow out the bottom drain holes. The first watering dissolves the salts, and the second washes the salts out of the soil.
For more information, consult the UC IPM Pest Notes: Houseplant Problems.
Ed Perry is the emeritus Environmental Horticultural Advisor for University of California Cooperative Extension (UCCE) in Stanislaus County where he worked for over 30 years.