Consulting Rosarian Advice for June
Article by Barbara Kemp, Master Rosarian
Multiple rain storms, pruning, and fertilizing in May brought healthy growth to our roses.
The first application of fertilizer was applied in May; continue fertilizing throughout the
summer every 4 to 6 weeks ending in mid-August. You will see how effectively our organic
products (Mile-Hi Rose Feed, kelp, and alfalfa meal) improve our soil and stimulate growth.
Now we must monitor pests and diseases and develop a watering cycle as our Colorado temperatures increase in June.
Integrated Pest Management is an alternative method to solve pest problems with roses by
using a less harmful means. In previous years, some considered pesticides as the first option to eliminate pests without considering our honey bees and other beneficials in the garden. A great way to monitor pests and diseases along
with observing the “beneficial” insects is to enjoy a morning walk in your rose garden(s). As roses become larger
and buds begin to appear, aphids may also become visible. With early detection, you can just remove aphids by
squishing or using an effective spray of water on the buds, blooms and foliage.
If you keep a garden diary, note your successes or problems and what you would do differently next year. Think of it
as an automatic to do list. If you decide that a more toxic solution (chemical) is needed for pest management, always
read the warning labels for application and disposal, and note any danger to pets. Also wear the appropriate clothing,
gloves, and mask as recommended on the manufacturer’s label.
Watering: There will be an increase in both frequency and amount of water to be used when temperatures climb into
the 80’s (water at least once a week) and even twice a week when temperatures are in the 90’s. The most efficient
and best time to water is early morning allowing leaves to dry and reducing the possibility of spreading disease
spores. Mature roses need about an inch of water per week. Use a soil probe to help determine moisture level.
You may find heat stress when temperatures are in the 80 to 90-plus range. Look for wilting shoots or leaves, scorch
on immature/mature leaves that are exposed to direct sunlight, or petal burn noticeable on red flowers. Use a deep root feeder to get the water down to the roots and then add 3 to 4 inches of mulch to maintain consistent soil temperatures at the base of the plant.