- 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/
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>