The supposedly Mediterranean climate and dry, predictable summers of central California and much of the West have yet to fully appear. When I last wrote, we had received upwards of 45″ of rain, but we were hoping for a timely end to the cool and wet season. Instead the rains continued into the first week of June and we now have had almost 62″ of rain, consistent night time temperatures in the low 40s, and days have rarely topped 65 degrees. Naturally, this has led to delays in planting, higher disease pressure and generally slow development of all crops, even those that prefer cooler growing conditions. Perhaps the best thing about all of the late rains and snow still lying deep in the Sierras is that our reservoirs and water infrastructure will be better able to supply the needs of agriculture, industry and ever-growing human demand. Might even be enough water left for the environment.

As in years past, this season we continue to explore crops that can be grown to achieve multiple purposes simultaneously, thus contributing some level of efficiency to an inherently labor and resource intensive endeavor. Perhaps the most striking example of one of these so called multipurpose crops would be common dill. This is a plant we grown principally as a fresh cut herb. However, if left in the ground past its prime fresh herb stage, once bolted, dill becomes a valuable resource for beneficial insects such as lady bugs and syrphid flies, a trap crop for tomato hornworms, a cut flower filler with a strong architectural presence and subtle chartreuse coloring, and finally dill seed for your value-added pickling projects. Rather than simply mowing and incorporating into the soil when we are done cutting the herb crop, we almost always leave it standing, without further irrigation, to accrue all of these additional benefits.

Dill seed is cheap and we have found it much easier to grow than its popular cut flower cousins Ammi majus and A. visnaga. Also in the Apiaceae, fennel, parsley, and celery, once running to flower, can also be used to great architectural effect in bouquets. The silvery blue stems and yellow flowers of fennel, and the deep green stems and bold yellows of parsley and celery are excellent foils to many of our more showy cuts. Bolted cilantro, if your customers like the fragrance, has been another good bouquet filler, beneficial insect attractant and source of coriander seed.

While this may be a stretch for some, at times we have even used bolted lettuce stalks sprouting from the base of harvested heads as a casual country filler. Probably no florist shop would ever be interested in such a look, but we occasionally have requests for all-edible bouquets, and bolted lettuce, with striking colors and a 7-10 day vase life, can be part of this mix. This works especially well with dark red varieties such as ‘Red Sails’, ‘Oscarde’ and ‘New Red Fire’. With each you get dark red leaves and reds and greens on the stem itself. Certainly rustic, but perhaps a good fit for some.

Similarly, we have been exploring the role cover crops can play in our mix of cut flower offerings. Depending on the species chosen, cover crops provide a multitude of soil fertility and soil quality management benefits: nutrient cycling, preventing nutrient leaching, building soil organic matter, nitrogen fixation from legume/rhizobacterial combinations, improvement of soil aggregate stability, weed suppression, reducing compaction, preventing erosion and pollinator forage. Cover crop seed is typically inexpensive when purchased in bulk, easy to direct sow, and many species have the added benefit of working well as fresh cut and dried flowers.

Phacelia tanacetifolia, grown principally as a bee forage, has a moderately strong taproot, provides good biomass to incorporate into the soil and produces gorgeous lavender blue flowers borne in twisting and turning fiddleneck-shaped clusters. Stems are generally 24-30″ long, easy to harvest and strip and last 7-10 days in water, continuing to open with no special treatment.

Virtually all of the cereal grains can work well as fresh and dried flowers. Normally we grow lots of the more expensive varieties like silver-tipped wheat, Highlander millet and ‘Ruby Silk’ teff. While not always as showy as their cut flower-specific relatives, we have been very pleased with our bulk plantings of cover crop and grain varieties of wheat, triticale, barley, millet, teff, rye, sudan Grass, and even the common cattle feed milo.

While I would never abandon the prime cut varieties, seeking out cover crop cereals which fill a cut flower niche, grow well in our environment, provide soil-building benefits such as improved aggregate stability, and can be grown at a fraction of the cost, seem like realm for ongoing exploration. Even the non-cereal grain quinoa is a crop to consider. While sacrificing its future food value, quinoa stems provide colorful spikes in a range of hues from green to pink to yellow to orange at a time of year when most of our crops are the more flat and dome shapes characteristic of the Asteraceae.

Several common cover crop legumes also readily cross over into the cut flower arena. Both crimson and red clover have been particularly useful for us. They can be purchased pre- rhizocoated so that you do not have to take extra steps to inoculate and thus benefit from their nitrogen-fixing capacities. In fact, we typically under-sow both of these species in existing cut flower and vegetable plantings. This strategy, assuming the increased plant density does not contribute to added disease pressure due to lack of air circulation, allows for nitrogen fixation right where and when more needy crops are growing, allows us to grow more than one crop simultaneously on the same piece of ground and provides more organic matter for incorporation when it is time to turn crops over. Again, these may not fit your market demands, but if they do, they can be inexpensive to grow, multipurpose crops that serve the soil, insects and your markets all at the same time. 

Finally, the most promising of the nitrogen fixing legumes is Crotolaria juncea, aka sun hemp. This is a fast-growing, upright, warm season annual that can fix up to 200 pounds of nitrogen per acre, provides substantial biomass for weed suppression, has a sturdy, deep taproot to break up compacted soils, and produce canary yellow, sweet pea-like flowers on upright stems. Like quinoa, the flower spikes are a welcome structural element later in the season when our bouquets are usually dominated by members of the aster family. Perhaps most importantly, the canary yellow flowers are both bold and beautiful in color and form and last up to ten days in plain water. Crotolaria requires cowpea inoculant to reach its full potential, and growers with mixed operations should note that it can be toxic fowl and some livestock. Multi-purpose, multi-functional, beautiful and cut-able, what more could you ask for?

Christof Bernau

UCSC Center for Agroecology

Christof Bernau UCSC Center for Agroecology Contact at [email protected]