Radishes Should Be Planted When Temperatures Begin to Cool

Q. I planted radish seeds in 8" deep planters using miracle grow potting soil . After approx. 10 days they grew up to approx. 3" developing 2 leaves and started falling over. They do not mature. The type of radish seed is Cherry Belle from Ferry Morse.  I've planted two different times and get the same results. What am I doing wrong?

A. It is usually considered too hot right now, with daytime temperatures still hundred degrees F, to plant radishes. They do much better when the temperatures begin to cool.

I would start planting them no earlier than about mid-October and you should be able to plant them throughout the winter in successive plantings up until about May when it gets too hot. Cherry Belle is an excellent radish and will do well here. Here are just a few of the many varieties we have grown in Las Vegas.

Chinese red meat radish

Radishes growing with irrigation from drip tape and straw mulch applied

French breakfast radish

White icicle radish

I have tried dozens of different radish varieties and not found a radish yet that does not like our climate. However radishes grown during the cooler months are not as spicy but sweeter than those grown in the hotter months.

Hold off for another month and try replanting the seed. The potting soil may also be a problem. Seeds like firm seed beds, not soft seed beds. I would take your soil amendments and mix it with existing native soil or good-quality sand and tried again.

After you work in your compost and prepare the area for planting, your shoes should not sink into the soil more than about 1/2 inch for a good seed bed. Radishes also grow well in containers.

Containers do not have to be terribly deep. 12 inch deep containers are adequate for radishes and allow the soil to drain and not become a problem for the plants.

So remember to use a soil mixture with compost or other soil amendment and make sure the seed that the seed bed is firm and not soft and fluffy. Watering twice a day until you see the seeds germinate should be enough. After they germinate water only once a day. I hope this helps.