September Garden Calendar: Heading Towards Fall Colors
Plan your September garden calendar appropriately because roughly 5% of the annual rainfall in a given calendar year will happen in the latter half of this month.
September ranges from bright and warm at the beginning of the month to the barest beginnings of the rainy season towards the end of the month. The primary concerns for gardening in September are the harvest time, and getting your garden ready for the winter months, and the rainy season.
It's Harvesting Time
Nearly every perennial fruit comes in with its first harvest load in September.
Apple harvesting in California starts a bit before Labor Day and extends through October, with the coastal regions having their harvest earlier than the interior, because the cooler weather at night triggers the ripening process.
Other fruits in need of harvesting at this time of year include pears, both Bosch and Anjou, and the last wave of summer pitted fruits, like nectarines, peaches and the last of the plums.
Most grapes should be harvested at this time of the year, and if you're interested in grape cuttings for next year, this is the time to head up to the Napa valley to get your hands on cuttings from the vineyards.
What To Do In Your Lawn
As the temperatures drop and the light settles, and in particular, as the rain comes in towards the end of the month, maintenance of your landscape design requires lawn care duties that change from regular watering to inspection for rusts and fungal parasites.
Look for reddish tinting on the grass – when you see it, spot apply some high nitrogen fertilizer. Be sure to mow regularly to promote a thick bed of grass to crowd out any weeds.
Towards the end of the September garden calendar, its time to start prepping your lawn for the winter.
Feed the roots – they grow actively throughout the winter months, and this is the time to put in a pre-emergent herbicide to prevent weeds next year.
Most of them will last about six to eight months, so the ones you applied in January through March probably need a new application, both on your lawn and on your rosebushes and philodendrons.
Granular weed prevention elements should be applied just before you water – water to half an inch, or apply just before it rains – these will help stop the usual growth and outbreaks of winter weeds.
There is Still Time for Planting
Yes, even though the summer is over, there's still time (and a need) to plant. If you started any potted fall plants in August, put it on your September garden calendar that it's time to transplant them to the garden (and take the plants they're replacing, re-pot them and put them in the greenhouse).
Cool season vegetables (lettuce, kohlrabi and Brussels sprouts) should be transplanted now.
Plant ground covers from flats, and transplant shrubs and trees from their containers – check to make sure the root ball is good before transplanting.
When prepping the soil, be sure to till it and aerate it, and amend it with organics from your clippings and compost pile to give your new seedlings plenty of material to grow from.
This is also the best time of the year to buy bulbs – the selection is the widest it will be all year. Buy them, and mark your September garden calendar, to put some in the refrigerator (especially tulips, crocus and hyacinth), to plant later.
You can plant daffodils, freesia, sparaxis and Dutch Iris now; they won't need much additional water past the winter rains we normally get. When you do plant a bulb, be sure to put a small dab of super-phosphate directly below the bulb.
While you're rotating your bulbs, be sure to lift and store your summer bulbs for next year, particularly your gladiolas and dahlias, so they're ready to be cycled into next year's landscape design. These can be kept nicely in pots over the winter in a green house, or refrigerated.
When you're choosing plants for your fall landscaping, keep the ultimate size and shape you want in the plant in mind, and keep in mind your drainage patterns and overall landscaping design at the forefront. Look for compact varieties of shrubs if you're trying to keep an enclosed space from turning into a jungle.
Watering Needs for September
The best news about the September garden calendar is that your watering needs will pretty much drop to nothing by the end of the month. Keep an eye on your lawn and your shrubs early in the month – we still have a hold over on August's hot temperatures, and this can lead to dehydration of your plants.
Apple harvesting in California starts a bit before Labor Day and extends through October, with the coastal regions having their harvest earlier than the interior, because the cooler weather at night triggers the ripening process.
Towards the end of the September garden calendar, its time to start prepping your lawn for the winter. 
Cool season vegetables (lettuce, kohlrabi and Brussels sprouts) should be transplanted now. 
You can plant daffodils, freesia, sparaxis and Dutch Iris now; they won't need much additional water past the winter rains we normally get. When you do plant a bulb, be sure to put a small dab of super-phosphate directly below the bulb.
