The month of May is one of the most important months in Tucson in regard to taking care of roses because of 100 degree temperatures which typically hit.
In early to mid-April, the annual spring bloom has taken place. In the last few weeks, old, spent blooms have been cut off plants just above 5-leaf sets. New growth is just starting to emerge from those leaf axils.
To help the process along so that strong, new canes ultimately emerge from these leaf axils, it is important to start the summer program on May 1.
Step one: Make sure that you fill potted roses with more high-quality potting soil up to 2 inches from the top. A great potting soil for roses is four parts Kellogg’s Patio Plus potting soil (can be purchased from Home Depot or Lowe’s), one part peat moss and one part perlite. Mix the products well in a wheelbarrow and then apply to pots that need to be filled.
Step two: On May 1, fertilize every rose with Osmocote Plus (15-9-12) and Milorganite (purchase Osmocote at Home Depot and Milorganite at Ace Hardware). For each product, apply approximately one handful of each product on the soil of each plant. Osmocote Plus states that it will last six months. Every time you water, a small amount of nutrients will be available to plants.
This product has all the major and minor nutrients needed to produce growth during the summer months. Milorganite features slow release nutrients as well with the added benefit of 4 percent iron. This one-two punch has produced steady growth during the summer despite scorching temperatures. Then you simply water each plant as required.
Step three: Add a mulch to all roses that are in the ground. An outstanding mulch is Gromulch made by Kellogg’s which can be purchased at Home Depot or Lowe’s. It is comprised of composted rice hulls, aged recycled forest products, aged arbor fines, composted dairy manure, composted poultry manure, gypsum, dehydrated poultry manure and hydrolyzed feather meal.
Water, water, water: As the temperatures hit 100 degrees, it is imperative to water your roses as much as they need it. For established rose bushes in pots, this means watering every day. For roses in the ground, you may be able to get away with watering once every other day. For new roses in small containers, you might have to water twice a day until the plants mature. While you can water any time of day, it is recommended that you water late in the afternoon after 6 p.m. during this time of year which allows for less evaporation. Also, it is advisable to put potted plants in an area that gets afternoon shade.
More Information On Shade
Lou Pavlovich of The Rose Society of Tucson wrote an article several years ago on how to construct a sturdy shade structure for your roses. To read this article, CLICK HERE.
Spray off your roses daily with water: The No.1 enemy of roses during the summer in Tucson are spider mites. Spider mites, which look like small salt-and-pepper particles under leaves, will suck the leaves dry until they turn light brown and fall off.
Keeping as much foliage on your plants is crucial to rose health during the summer. Every morning, spray off your roses with a jet of water supplied by a Fogg-It nozzle (heavy volume, 4 gallons per minute) attached to your water hose. You can purchase this great nozzle at www.amazon.com for about $10.
Make sure you spray underneath the leaves of the plant. By doing this daily, it will prevent spider mites from getting started. The added benefit is adding humidity to your garden which is vital in Tucson’s arid summer conditions.
