By Gary Jones

Not that you need an excuse to use black plants in your garden, but the Halloween season is the perfect time to add dark and rich colors.

Fall is California’s best planting time and whose garden doesn’t need a bit of a pick-me-up after an unusually hot and dry San Diego summer? Just a handful of plants with foliage and flowers that are black, red, purple or orange can put your garden in a fall — or even a bit mysterious — mood.

Topping your shopping list should be coral bells (Heucheras). You’re not going to be planting these for their dainty bell flowers — it’s the foliage that’s killer. Black-purple. Bronzy-red. Silver with black veins. Orange and peach. There are many, many varieties, but you may need to visit several nurseries to see all the possibilities. Unthirsty coral bells are perfect for areas with dappled sun and dry soil.

Next on your list should be grasses, especially the dark purple or black ones. Black mondo grass is always a kick, but consider Japanese blood grass (Imperata cylindrica “Rubra”) and the wonderful and dramatic new millet grasses “Purple Majesty” (dark purple-red) and “Jade Princess” (chartreuse foliage with big, black grain heads). If these are hard to scare up, red fountain grass always looks great.

Don’t forget that there are wonderful red-leaved New Zealand flaxes and similar-looking cordylines. “Festival Grass” is one of the best, with very dark, red-black spidery leaves.

The easy-to-grow succulent “Zwartkop” is composed of striking black rosettes of foliage. But if you’re looking for flower power, you can’t do better than the bright orange-red daisy flowers of “Mystic” dahlia with its lacy black leaves. This type of dahlia comes in bright yellow, rust and purple, too.

Two fall bloomers that will fit in to your warm and moody theme are black-eyed Susans and coneflowers. Both of these sturdy heat-lovers have had major makeovers. The color range and flower form changes of coneflowers is pretty remarkable; you might not even recognize them. Colors include papaya, hot pink, burnt orange, chrome yellow, creamy white, pinky purple and rust. Black-eyed Susans are now lime, rust, brown and yellow. Some have even lost their black eyes.

Ornamental peppers are having a moment and it’s a great one. The small, upward facing peppers (yes, they’re edible) are intense red, bright orange, yellow, cream and purple. And many of them have beautifully contrasting foliage of black, purple or variegated white, purple and green.

If you’re really looking for some drama, the elephant ear (Colocasia) “Black Magic” will do the trick and be a treat. The large, shield-shaped leaves are as black and mysterious as a plant gets.

All these plants can be used to spice up borders and boring garden corners. And since these colors all combine beautifully, any combination can be used to compose a container. Set one on your porch and you’ve instantly got a moody, if not spooky, autumn welcome.

—Gary Jones is the Chief Horticulturist at Armstrong Garden Centers. Email him your gardening questions to growingdialogue@armstronggarden.com.