Fertilization

Click on the categories below to learn more about fertilization.

Lawn

You should fertilize your lawn twice a year. Fall and mid-spring are the best times to fertilize most grasses. Grasses store fertilizer as food during the fall in order to survive through the winter. During the spring, lawns need a boost, and more fertilizer will provide much needed food for your lawn during the faster-growing spring and summer seasons. Lawns have specific fertilizer requirements, depending on the season and the type of turfgrass you grow. Read the instructions on the package carefully before purchasing. Lawn fertilizers containing various percentages of nitrogen, phosphorus and potassium are common lawn foods. Nitrogen is the nutrient required most by lawns and the main ingredient to consider when choosing lawn fertilizers. Controlled-release, or slow-release nitrogen sources are preferred for most applications to lawns.

Plants

If you use a good mulch for your plants, you may not need to use fertilizer. When mulch breaks down, it supplies the right amount of nutrients for your plants. If you don’t use mulch regularly, common plants can benefit from fertilization especially with poor soil conditions. Basic fertilizers should be used once a month or when plant deficiencies are noticed. Slow-release fertilizers should only be used twice a year, during the spring and summer. It’s usually not necessary to fertilize your plants in the fall because they grow more slowly during the cooler winter months.

Azaleas / Camellias / Rhododendrons

These types of plants require special fertilizer. Azaleas, camellias and rhododendrons (among other plants) prefer acidic soil (soil with a low pH), so it is very important to use fertilizer designed with this in mind. Spring is a good time to fertilize these plants, but only after they have finished blooming and have been trimmed.

Palms

Palm trees have very specific nutrient needs, so you should use fertilizer specially designed for palm trees. Palms should be fertilized twice a year, once in March and once in July. Remember to read the instructions that come with your fertilizer to ensure that you use it properly. Different sized trees have different fertilizer needs. Avoid putting fertilizer on the trunk of a palm tree. Also, if you notice that your palm seems a little droopy, it might be suffering from not enough water.

Compost

Another way to provide nutrients to your San Diego plants is by amending the existing soil with compost. Compost is essentially decomposed organic matter. If your soil lacks organic material, is compacted or doesn’t retain water, compost makes a great amendment. Different soil types will need different applications of compost to create the same increase in organic matter in the final mix. Compost can be purchased at a local nursery in bags or can be purchased by the cubic yard.

Gypsum

You can use gypsum in hard clay soils as a soil conditioner. Gypsum is a great soil aerator that loosens soil structure allowing plant roots to more easily penetrate soil. Apply gypsum to clay soils before seeding or sodding lawns, or sprinkle it on existing lawns or flower beds. Gypsum can be applied at any time during the year, does not change the soil PH, is not harnful to humans or pets and will not burn plants.

It is a good rule of thumb to water immediately after fertilizing lawns and plants to eliminate the risk of burning the plants. Always follow the directions on the fertilizer’s label for best results.