Will I need to irrigate? What are the water requirements for the PAm seed mixes?
All of the seed mixes offered by Project Apis m. have been developed with California’s unique water issues in mind. The cover crops we offer will perform satisfactorily with the average amount of rainfall in most of California’s almond growing regions. If planted by the beginning of October, the PAm Brassica Mix will grow into a full mature stand using only rain water. In a wet year, the Northern region of California will have enough rainfall to grow the PAm Clover mix. However, supplementing with irrigation will help the performance of cover crops. In general, the PAm Brassica Mix will do fine with rain water alone, and the PAm clover mix will probably need some additional water with irrigation. It is still important to monitor all factors like planting date, weather, soil moisture, and orchard irrigation schedule when determining irrigation requirements for the PAm cover crop mixes.
Calculating these factors can be a challenge.
A key hint about water: the earlier the seed gets planted the more rain it will get, thus reducing the need for irrigation.
Ongoing research from Dr. Dani Lightle, Cynthia Crézé, and Dr. Amélie Gaudin is addressing some important questions regarding cover crops and their role in soil organic matter, water use, pest pressure, and greenhouse gas emissions. The preliminary results on the effects of frost are intriguing. They found orchard floors with cover crops were cooler by a few degrees than those with bare ground or resident vegetation. However, at a height of 5 feet above ground the average temperatures of the orchard with a cover crop and without were the same (2) (see Figure 3 below). Research into temperature dynamics is continuing.
2. Lightle, D. Crézé, C. Gaudin, A. 2018. Cover Crops in Almonds: Research Updates. UCCE Tehama County Fruit and Nut Notes
How important is weed control prior to planting? Do I need to use herbicide?
All of our seed mixes should be planted in the fall, at this time weeds are typically mature and do not hinder the plantings. The PAm Brassica Mix grows very fast and will outcompete most weeds in almond orchards. Weed control is a key benefit of cover crops. The Pam Clover Mix has a slower rate of growth and might benefit from an herbicide application prior to planting. Any broadleaf, grass specific, or broad spectrum herbicide will benefit the clover mix to get established.
Most almond orchards have a weed free floor by the fall. The majority of the Seeds for Bees growers do not apply herbicide prior to planting. However, if weeds are an issue in a particular orchard block or location, using herbicide, burning, or solarization before planting will only help the health of the stand.
What type of planting method is the best?
Great stands of bee forage cover crops can be grown with various methods. What works best is the “no till drill” method. This planting implement works great on non-productive areas of the farm as well as orchards that have been subject to compaction.
Visit the PAm Seed Mixes page, for specific instructions, planting methods and rates, and technical advice for each seed mix.
Will a nearby flowering crop divert honey bees away from the almond bloom?
This is an understandable concern on the part of almond growers. The efficient pollination of your crop is top priority. In-the-field research shows that providing honey bees forage prior to almond bloom can actually increase the frames (or numbers of bees) and that these bees are healthier and more robust to pollinate your crop.
Your almonds provide bees with large quantities of high protein pollen in a relatively small area, making it very easy for bees to collect. Bees want to work almonds!
Bees generally have worked all the pollen from almond trees by mid-afternoon – targeting almond pollen before moving on to other pollen sources.
By design, the anthers on the almond flower readily display the pollen, making it very attractive to honey bees.