I tried Daikon radishes one year, probably too early or too c old (or something else wrong). The roots were TINY, but I let them grow and bloom (very pretty). The tons of radish pods were delicious!
Next year, I got a few roots 6-8" long ... but much too hot for me.
P.S.
>> add extra sand, vermiculite, compost and work it in good
Can't beat lots of compost! I'm a big fan of pine bark, or any evergreen bark. For softening clay soil, I like well shredded bark fines. It's like peat moss, but provides loft for 2-3 years instead of 4-5 months.
For aeration, small bark nuggets.
For top-dress mulch, large bark nuggets or wood chips.
Whatever bark product I buy, I screen it, and then use the different sizes in different ways. I even use it for potting mix and seed-starting mix.
