Aaaah, autumn! It's perfect time to entertain outdoors -- most of bugs are gone, sun isn't scorching even though it's warm enough to enjoy an afternoon or evening al fresco, and there's a bounty of good things to serve for an outdoor meal. Because days are shorter in autumn, outdoor entertaining in fall calls for special attention to lighting and temperature.
Lighting
The earlier sunset will afford you an ideal opportunity to bathe your outdoor space in evening lights. Use soft light, but use plenty of it. Try dozens of votive candles in jars and glasses to protect flame from wind, hurricane lamps, or kerosene lanterns set on low. Create cozy seating areas and equip each with a glowing light source.
Heating
The method you'll use to chase chill from night will vary depending on your climate and your outdoor space. If you have a yard (and community by-laws allow), a campfire is a wonderful informal party setting. In smaller gardens, consider self-contained fire pits or a chimenea.
For a more formal affair, you can install a propane-powered heater. These units are available in a range of heating powers and prices. Or, drape attractive throws or quilts on each chair for your guests to wrap around their shoulders to ward off night air.
Of course, you'll want to take advantage of wonderful colors and textures of autumn in your decorating scheme and table settings.
Color
Autumn's colors are deep and rich -- russet, crimson, burnt orange, gold, dark green, and color of hay. Use these hues repeatedly in tablecloths and settings, flowers, centerpieces, and even food. Scoop out pumpkins and other squash and fit them with containers of water to make vases. Mass potted mums in vivid colors. Use orange Chinese lanterns, bright rosehips, stems of red or orange berries, or chilies. Wrap vibrant maple or sumac leaves around votive candleholders or napkin rings. Sunflower heads can be strewn on tabletop, or left on flower stalks in a container.