In many parts of the country, spring is the only time you think about fertilizing your yard. But in the East Valley—Mesa, Gilbert, Chandler, Tempe, and Scottsdale—our plants follow a unique double growing season separated by a brutal summer heat dormancy.
To get the best results from your citrus, ornamental trees, gardens, and lawns, you must align your fertilizing with our local seasonal shifts. Here is the calendar schedule we use at Bug & Bloom to keep East Valley yards thriving.
1. The Spring Push (February – March)
As temperatures begin to warm up in late February, desert plants and citrus wake up from their winter rest. They prepare to push out new leaves and flower buds. This is the most critical fertilizing window of the year.
- Citrus: Apply a deep-root injection of chelated iron, zinc, and humates. This gives the tree the iron it needs to prevent leaf yellowing (chlorosis) during the heavy spring growth.
- Lawns: Apply a light top dressing of fine compost or spray compost tea to stimulate soil biology as the grass wakes up.
- Desert Trees: Mesquites and Palo Verdes generally do not need heavy fertilization, but stressed trees benefit from a mycorrhizal root injection.
2. The Pre-Summer Support (May)
By May, the spring growth surge has slowed, and plants are preparing for the extreme heat of June, July, and August. Our goal in May is not to force rapid new growth, but to build cellular strength and heat resistance.
- All plants: Avoid high-nitrogen chemical fertilizers in May. High nitrogen forces tender, watery new leaves that will instantly scorch in 115°F heat. Instead, apply kelp meal, seaweed extracts, and humic acids. These natural amendments contain potassium and trace minerals that strengthen plant cell walls, helping them retain water and resist heat stress.
3. The Summer Dormancy (June – August) — DO NOT FERTILIZE
When temperatures exceed 105°F, most landscape plants enter a semi-dormant state. They stop growing to conserve energy and water. Never apply fertilizer during this window. Forcing a plant to grow when it is trying to rest stresses its system and can lead to sudden dieback. Focus entirely on deep, consistent watering and shading.
4. The Fall Recovery (September – October)
As nighttime temperatures begin to drop in September, plants experience a second, minor growing season. They recover from summer stress and build root reserves before winter.
- Citrus & Trees: A fall application of deep-root nutrients helps replenish the energy spent surviving the summer. It supports root development throughout the mild winter months.
- Winter Gardens: Prepare your fall vegetable beds with rich compost and soil microbes to support winter production.