I used the Secret Spot in a small logging road plot last year. Wasn't impressed at all. The only thing that did well and stayed was the ryegrass. Ryegrass will make your plot look good but is actually a poor forage choice for deer. The few brassicas that did emerge, fizzled out pretty quick.
The brassicas will grow this time of year, but you could safely wait a few weeks to plant them and it wouldnt cost you. When are you planning on hunting this plot? Deer in my area dont touch the brassicas until late fall so if you want to sit on your plot opening day of archery there are better choices.
Brassicas stated time to maturity is 45 days is it not, but that is likely in Ideal conditions.
Depending on what else they have to eat they may not touch them til they get that frost nip...in say mid October, that is why many plant them in early-mid August as a Fall/winter plot, cause even then you got 60-75 days to get them mature before they get the frost nip and turn into big lollipops.
You can plant brassicas now, but then you got to worry about the hot dry dog days of summer stretch. They like water and come frost your plants may be past prime.
I planted secret spot and agree with Bonzy...looks great and deer eat <u>young </u>ryegrass, but you will be spraying that plot in future years to kill it as it takes over.
I planted Shot Plot here last fall and think it's a good product but it doesn't seem like the deer around here care too much for brassicas. I think it all depends on what other foods they have available to them. I HAVE found that the deer here love oats. I'm planning on doing an oat/rye/winter wheat plot for this fall instead of brassicas. It would be nice to just do oats but they die off after a few hard frosts.