top of page

Summer in the Garden

July & August in the Garden by Joe McDade

Summer Has Arrived..... Help Your Garden Cope May and June have been kind to your garden as it wasn’t until the end of June that our temperatures started to climb over the 100° mark. With the Summer Solstice behind us, get ready to experience changes in our environment. Along with the predictable rise in temperatures, you can’t help but notice the healthy growth our vege- tation has undergone, especially native trees, which is a direct result of our wonderful winter rainfall.

Your Garden Will Slow Down Your garden has now started to go through a metamorphosis that is not visible. It is entering a slowdown period when gardening comes to a standstill, starting in July and continuing into August. It’s just not a good time to do any serious planting. The rise in temperature will continue in July and into August ac- companied by, hopefully, the arrival of the monsoon which will bring welcome relief.

Summer Tasks In the meantime, there are three major tasks that you need to concentrate on during these months:

  1. Pruning- especially native trees.

  2. Watering and

  3. Preventing Heat Stress.

Remember, planting should be avoided during these two months

Pruning Native Trees Summer is the recommended time to prune native desert trees because they are actively growing and can recover quickly. Things to consider before undertaking this task: Good pruning is both an art and a science. The result should be a safe, healthy and beautiful tree that complements its natural growth. If you prune your trees yourself, become familiar with proper pruning principals and techniques. There is a lot of literature available, especially the internet. If you hire someone to prune your trees, be sure they understand proper pruning principals and techniques.

  • Remove no more than one-quarter of a tree’s branches in a year. Cutting off too much foliage “starves” the plant by reducing its ability to synthesize and can leave it susceptible to disease.

  • It’s advisable to hold off any pruning for at least one year after planting. Two years is even better. If you allow as many branches as possible to survive, the tree will develop strength and trunk girth.

  • Keep in mind that the longer you wait to prune your mesquites, the higher the risk of wind damage during the monsoon.

Last month I discussed How Much and How Often in some detail. I’d like to add to that with some specific tips:

Landscape Plants Watering

  • Increase water application as the weather warms. Pay attention to irrigation needs of plants.

  • Apply mulch to the ground around the base of heat sensitive plants to keep the roots cooler and prevent evaporation. Keep the mulch several inches away from the trunk.


  • Cut back on fertilizing established roses to encourage plants to slow down for the hot summer.

  • Water deeply as temperatures climb.

  • Hose off plants in the early morning to increase humidity and control spider mites.

  • Toward the end of August and into September, add an iron supplement if roses show yellowing from iron deficiency.

Succulents Succulents are normally drought resistant. However, we’re at that point in the summer where they too will succumb, especially to the high nighttime tempera- tures. When the night temperatures stay at 90o or above and the humidity is high, most succulent plants can’t breathe. After several nights in a row, chances are many of them will rot. Other than careful watering, there is nothing that can be done. **Remember, many plant families make up the succulent species, the best known being cactus. Virtually all cacti (or cactuses) are succulents, but many succulents are not cactus**.

Annual Flowers Growing annual flowers in containers is relatively simple in fall, winter and early spring, while summer can be another matter entirely as soil temperatures heat up to triple digits, and roots will “cook” without adequate moisture. Containers in full sun often require daily watering which results in nutrients being leached out of the soil. It is a challenge!

Citrus Our hot weather will easily stress your citrus trees for water which results in fruit rinds becoming tough. Later in fall, rinds will crack and split because they are unable to expand as the fruit increases in size. Water mature trees every 10 to 14 days to a depth of 3 feet. Newly planted trees need water every 5 to 7 days to a depth of about 2 feet (or through the entire root ball). Note****Citrus will let you know when they are stressed as they will literally look like they are begging for water. When that happens, consider soaking with a soaker hose.

Trees Currently, your native trees are in good shape thanks to our abundant winter rain. If our monsoon is a bust, keep an eye on them and, if need be, consider soaking them.

Heat Stress...Understand It, Recognize It And Deal With It!

Heat Stress occurs in your garden when temperatures reach above 110 degrees in a four day span which happened multiple times last summer and has already occurred in June.

  1. You need to increase the frequency of watering when temperatures are consistently above 110 degrees. Water deeply and infrequently as we often water them too often and too shallow for it to do much good. Deep watering is the proper method for irrigating plants because it encourages deep root growth where the soil is cooler and stays moister for longer. During the heatwave, water deeply every four days. On average, 2 hours is the length of time to irrigate to the desired depth.

  2. Shrubs should be watered to a depth of 2 feet and perennials and groundcovers to 18 inches.

  3. Don’t fertilize. Feeding plants simply makes them work harder to produce new growth when all they are trying to do is deal with the heat.

  4. Don’t prune away heat-damaged growth until September and the weather is more normal. Those ugly leaves are protecting the interior of the plant.

Happy 4th of July.......See You In September! Think Football! (If you have a gardening question, please contact the Maricopa County Plant Hotline


bottom of page