Cover Cropping, Summer 2011

Sunchoke flowers in the foreground, Buckwheat in the middle and Sunnhemp in the background.

Summer in South Florida is not just about fruit, it’s about cover crops.  I learned the benefits of cover cropping early on in my agricultural education, but it wasn’t until I was working my own soil that I REALLY knew just how valuable and effective they can be.  As I’ve mentioned before, I take as much care in seeding beds of cover crops as I do any veggies.  It’s important to get even germination and consistent growth.  It’s also important to know what types of crops will do well, when to plant them, how much to water them, at what rate and to what size they will grow and of coarse the length of their life cycle.  Theoretically any plant can be a cover crop.  The requirements are completely time and place sensitive, meaning, if they perform a certain way in a certain place at a certain time, they can be considered useful as a cover crop.  Most of the crops used by farmers are the ones that have been tested, tried and true, for their particular seasons, climate and soil.  A cover crop should germinate easily, grow fast and dense, forage for nutrients, either attract beneficial insects or repel pests and should not be persistent.

This summer I’m focusing on two particular crops, which I have found, through research and personal experience, to perform really well in the South Florida heat.  Buckwheat gave me a quick cover crop in June and I’m preparing to sow Sunn Hemp, which will grow very tall throughout the rest of summer until I’m ready to start planting vegetables in September.  Buckwheat is a heat loving herbaceous plant with a very short life cycle.  It grows more rapidly and dense than most weeds, making it a great weed blocker.  It also accumulates calcium which is left behind when the plants are cut down or tilled in.  Buckwheat grows no taller then waist high and blooms within 30 days, attracting hoards of bees and wasps.  It’s fast growth allows for planting two or three different crops per season.  After the Buckwheat I’m sowing Sunn Hemp, which is also a fast growing crop, but it gets to be about 15 feet tall before it blooms, which takes between 60 and 90 days.  The benefits of Sunn Hemp are that it grows very dense, blocking weeds and producing the highest amount of organic matter of all cover crops commonly grown, which is also partly because it is very fibrous.  It’s a prolific nitrogen fixer, it is drought and wet tolerant, it has a deep tap root which helps to break up subsoil and it’s flowers attract bees and are edible!  When I cut it down in September I will have straw for mulch and a loose, crumbly, nitrogen rich soil.

Field of flowering Buckwheat

The same Buckwheat field after we cut it down to prepare for a second cover crop, this time Sunn Hemp (which is already growing in the far right corner).

Some of the buckwheat was left in the field for a little bit too long and it was stating to begin a second cycle. The old plants bloomed, went to seed and dried up, creating the perfect mulch for the seeds to germinate and start the process all over again. Very interesting!