Radishes Gone Wild

I have this small trashy spot in my garden where the weedy things grow. It is seldom watered, unless it rains, so the residents are a mix of true weeds and weedy vegetables - renegades from the managed chaos of my garden beds.

Three years ago, I started an interplanted bed of chard, peas and radishes – odd but functional companions. After a late spring hot spell wilted down the peas and left a snaggletooth edge of radishes gone hot, I got brilliant and decided to grow my own radish seeds. Of course, my mixture of White Icicle, Black Spanish and Breakfast Radishes all came to bloom about the same time, much to the bees’ delight. Like all good members of the same species, they readily cross-pollinated providing me with abundant seeds of questionable heritage. The next spring their progeny proved to be exceptionally vigorous and wickedly bitter White Icicle types. Looked good, grew great, but were utterly inedible, except for the green seedpods. I sprouted the remaining seeds and ate them.

But, that wasn’t the end for them. A couple of plants took to this weedy spot and continued without my assistance or intervention – a difficult accomplishment
for most food plants, and impossible for others. The hybrid form seems stable, with a few large white rooted radishes sprouting and growing each year, almost daring me to investigate the intricacies of root crops.

These crossed radishes defy one of the basic tenets of domestic root crop growth – when nutrients and water are short, put your energy into flowers and seeds, not fat juicy storage roots to feed your keepers. These plants have consistently large roots in relationship to vegetative growth, which never becomes lush and tall.
I still have no answers for this behavior, in spite of acquiring an understanding of root crop requirements.

Here are some tips I picked up for growing great radishes:

• All varieties will cross-pollinate – so take precautions when growing for seed.
• The harvest period for spring radishes is short, but the pithy ones will bloom and produce tasty seedpods that are great raw and in stir-fried dishes.
• Optimum temperatures for growth are 60°-70°F – colder and they will grow slowly and become bitter – hotter and they will be pithy
• Plant when soil temperatures hold at 45°F
• There is a relationship between the root size and planting depth – for normal size roots sow seed ½” deep and 1” apart – for larger roots sow seed 1½” deep and 1½” apart.
• Spring radishes are day length sensitive with 12 hour days being optimum – longer days stimulate bolting. (Winter radishes are biennials)
• Radishes need consistent moisture, moderately rich soil and optimum growing temperatures to create those sweet juicy roots.
• Time to harvest ranges between 18 and 35 days, beyond that pulpiness sets in.
• There are exceptions to these generalizations about spring radishes.
• These generalizations do not apply to either winter or daikon radishes.

Now is the time to plant spring radishes – soil and air temperatures are as close to optimum as we will get during our short spring.