September 21, 2013

1 - Powdery mildew on apple trees will not make the fruit unsafe.

2 - Now is the time to plant bulbs and spring flowering perennials.

Yard and Garden September 21, 2013

Q. #1

Is it safe to eat apples that were harvested from a backyard tree with powdery mildew?

A. #1

If the trees were not sprayed with fungicide or other pest control agents, the apples should be safe to eat. Powdery mildew and most plant diseases do not infect people, but I would wash the apples well anyway.

People are rarely infected by fungal diseases that may be contracted through a wound when handling packing material around some nursery stock. This is rare, but it is rare and unexpected it is difficult to diagnose, so gardeners should be prepared to tell their doctors if they have handled the moist packing material around roots of bare root trees or similar substances. Once again, this is rare. Eating fruit from trees with foliar diseases like powdery mildew or similar fungi is not hazardous.

If the fruit had been injured by hail or insects and begun to rot, then there would be cause for concern. Your local NMSU Extension Home Economics agent can help you determine if that is the case. Food safety is an important issue.

If the trees were sprayed, potential hazards will depend on what they sprayed and when they applied. The labels on any products used should tell how long before harvest to stop applying the product. Your local NMSU County Extension Service agent can help you find this information and explain it if necessary.

Q. #2

Is now a good time to plant fall bulbs for spring flowers?

A. #2

Yes. Most garden centers have bulb and other perennial plants that can over winter and bloom in the spring. Now is a good time to plant them. If you have been fortunate to have had recent rains, the soil should be easy to dig and prepare for planting these plants.

For most bulbs and perennials, loosen the soil deeply; and thoroughly work compost or other organic amendments and a source of phosphate (bone meal or commercial phosphate fertilizer) into the soil. In our organic soils, bone meal will not readily release the phosphorous into the soil without organic matter or sulfur to increase the soil acidity. Commercial phosphate fertilizers may be more effective in soils with low levels of organic matter.

After the planting bed is properly prepared, plant the bulbs at the depth recommended for each species. Some must be planted quite deeply, others, such as peonies, should be shallowly planted. After planting, moisten the soil and irrigate once every 3 weeks to once a month through the winter. Roots will be developing and must have moisture. In late winter, water is important as the flower stalks elongate. Lack of moisture will result in stunting of the flower stalks. If there is adequate winter moisture to maintain soil moisture at the depth of the bulbs you will not need to irrigate, but since we often lack sufficient winter moisture some irrigation is usually necessary. Organic mulch can also help maintain soil moisture and provides an additional benefit by moderating changes in soil temperature as the weather changes.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email:, office: 505-865-7340, ext. 113.


For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at, or at the Desert Blooms Facebook page.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!