I've always considered Halloween the jumping-off point for getting the first batch of cool-season annuals in the ground.
You may have planted some pansies or snapdragons earlier, but those that get planted on Halloween or later are the ones that will look the best in November, December and January.
Cool season annuals such as snapdragons, pansies, sweet alyssum, ornamental kale and cabbage will not only survive, but thrive, if you follow my recommended flower-planting technique. Frankly, it not only works for annuals, but for perennials and even small flowering shrubs. I've used this regimen for years, and it has never failed me. It ensures good soil for delicate roots, an organically rich environment to encourage even more roots, and includes a controlled-release blooming-plant food that should last for at least three months.
Here's how it works. First, push aside as much mulch as possible from the area in a raised bed where you intend to replant an annual from a four-inch pot. Mix in a couple inches of fresh rose soil. Take the annual out of its pot and dip the root ball into a solution of Medina Hasta Gro liquid plant food. (I have also, from time to time, added a capful of the vitamin/hormone supplement Super Thrive to the five-gallon bucket I use for the transplant solution.)
Then, insert the plant delicately into the new rose soil-amended area, spreading out the wet root system. Before you push the mulch back into place, or add new mulch, side-dress the area with a little Nelson's Color Star — that's the slow-release blooming-plant food of choice for me. There are others, like Carl Pool Colorscapes and Fertilome's Start-N-Grow, but none are more readily available than Color Star. There are also organic formulas, such as Microlife's Max Blooms and standard all-purpose organic plant foods like Soil Mender's Yum Yum Mix.
Finally, the mulch goes back into place.
As long as your color pockets stay consistently watered during the first two weeks, you will have great results through January without having to spray them every two weeks with water-soluble plant foods. You might need to give them another shot of slow-release plant food again by January or February, but that's it.
Some important things to remember:
- Don't use anything considered "potting soil" in outdoor beds. If you want to use this technique with potting soil, keep the plants in pots.
- If you have to re-do an entire bed with fresh rose soil, as opposed to just making amendments for color pockets, allow the bed to rest for at least two weeks before planting anything in there. Consider saturating any newly made beds with soil activator weekly for three weeks, to help mellow the soil and protect delicate roots from a "hot reaction."
- Try to incorporate one bag of rose soil (on an existing bed) per flat of annuals.
- If you don't use my concoction above, please don't use anything considered a "root stimulator" unless it is 100 percent organic.