Home & Garden

If well-adapted species are selected for the landscape then Woody plants (including trees and shrubs) tend to have fewer soil challenges than other home garden uses.

There’s a problem with my plants.

What’s likely causing the problem with your plants?

Many nutrient deficiencies cause yellowing or discoloration of plants.
If the plant is deformed or dead, it's likely not a soil problem (unless you killed it through lack of water!)

Still think the issue is with your soil?

Check soil pH and
Check your soil texture

For more: Want to understand your soil more?

Explore Soil Doctor (Bell)

Know your soils Fact sheet (Ingles)

What's my soil? Soil web (T O’Geen) is a remarkable resource showing soil types throughout California with detailed information on soil characteristics and potential uses.

How can I improve my soil?

Practices to improve your garden soil

Adjust Soil pH
Check your soil texture
Raised beds (for problem soils)
Add Soil Amendments
- Fertilizer
- Compost, mulch and more
Eeeck Bugs
Water & Irrigation

Soil pH

Is my soil pH okay?

For most plants, a soil pH between 5.5 and 7.5 is okay. (pH is basically the measure of the amount of acid or base in the soil)

See how nutrient availability and microbe activity vary with pH (Figure from Fairway Green Inc)

Note: Some indicator plants can help diagnose soil pH characteristics (e.g., Marigolds - get Fe and Mn toxicity at low pH; Petunias - show Fe chlorosis at high pH).

Want more? See "What is pH and Why do we care" Fact sheet

How do I measure my soil pH?

There are a number of pH measuring devices sold at garden shops (See some common types of pH meters - with outdated costs).

Many pH measuring devices are not very accurate although they can give a general indication of whether you are near an extreme.

pH litmus Paper is usually okay.

If you want an accurate measure, you may need to send your soil sample to a lab or get an upscale pH meter. (see Basics and Soil Sampling for more)

How can I fix my soil pH?

Is soil pH a problem Fact Sheet (Blakey)

In summary

Note that your actions depend on soil texture because a clay has more buffering than a sand. A such, a clay needs more additive to change its pH.

If pH > 8 (alkaline) One option is to add Sulfur - how much, when?

if pH < 6 (acid) - one option is to apply lime. how much, when?)

Soil Texture

How do I estimate soil texture

Estimating soil texture by feel Video (Madden)

Estimating soil texture by feel Fact sheet (Ilaco)

Is my soil stable?

Soil stability test video (NRCS) (1:13)

How do I interpret soil texture

In summary:

Sandy soils have low available water and few nutrients
Loam soils (a mix of sand, silt and clay) are the best for water and nutrients
Clay soils hold lots of everything - but they hold water really tightly. As a result, a heavy clay might actually have more total water in it than a loam, but less of the water is available to the plant. Clays also may waterlog or have slow infiltration. Further, there ar two different types of clay soils. Swelling clays are typically richer than the non-swelling types.

What can I do

In summary, virtually all soils benefit if you add compost, mulch and/or manure.

Gardening and landscaping in hard pan soils Fact Sheet

Managing clay soils Fact Sheet

Also see

Raised beds
Fertilizer and Amendments.

Raised beds

Use when your existing soil is really problematic (e.g., very poor drainage, salty, rocky, etc.), or

Use for convenience and/or appearances (Raised beds can look nice and neat!).

Raised Beds Fact sheet (Blakey)

Soil preparation

Lawns web (UC IPM)

Vegetable garden Fact sheet

Woody plants

Site preparation web (UC IPM)

Should I use amendments in planting a tree or shrub? Fact sheet

Soils where you plant woody pants. Grow the right plant in the right place. (See UC Master Gardeners)

Soil amendments

Why use amendments?

Garden soils. Soil amendments (such as mulch, compost) are the most common and promising option to build soil health and improve the soil tilth of home garden soils.
Fertilizer - Plants get their nutrients from the soil and from added amendments (like compost or manure, or fertilizer etc.). Some nutrients might also come in the water.
Mulch - (almost) anything that goes on the surface - is good for reducing soil evaporation and suppressing weeds.
Compost - decomposed organic matter added to the soil - is good for soil microbes, for building soil organic matter and for supplying nutrients.

Composting is good for your garden and the environment Fact Sheet