There are 162 days until Thanksgiving, so you’d better hurry if you plan on decorating this year. For a cornucopia of color, get your seeds in the ground before the end of June, popping in everything you need to stuff that horn in November.
Start by planting two staples of fall décor – miniature gourds and tiny pumpkins. These must-have accents nestle into centerpieces and are easy to grow in our hot, dry summer. Each vine produces enough decorative fruit to make any decorator happy, but because they like to ramble, give them room or train them up a trellis. 
Customize your plants to fit your decorator’s style, by planting a mix of orange and white mini pumpkins. If you favor a flat pumpkin, orange Jack be Little or white Baby Boo is what you need. But for perfectly round, miniature Jack O’ Lanterns, check out Little October at Botanical Interests .
For a striking red accent, grow Love Lies Bleeding (Amaranthus caudatus), an amaranth with long, pendulous seed heads. Pop in full sun, giving these three-to-four feet tall plants elbow room and a stake for support. Water, but keep them a bit on the dry side. Clip mature flowers and hang them in a cool, dark location to dry. Seeds of change has this.
Ornamental corn is available in a variety of sizes and colors, from diminutive, two-inch strawberry ears to huge, nine-inch Seneca Red Stalker whose stalks and ears delight in fall on porches, tables, and doors. Direct sow seeds in full sun, planting at least five rows to ensure pollination. Water often so ears get large, then wait to harvest until after the silk turns completely brown and the kernels are dry and hard. 
Pluck the ears from the stalk by pulling them down, peel back the husk to reveal the kernels, and then hang upside down in a cool, dry location that is free of mice. Leave the husk attached to the cob for a decorative look, or peel it completely off before drying the ears. For a large selection of colors and sizes, check out Seed Savers Exchange .
Normally seen springing up from straw mulch by accident, wheat is an unusual addition to cut flower gardens. But its spiky, bearded seed heads are gorgeous in arrangements and bundled in sheaves on the table. Plant it like grass seed by sowing onto a prepared bed, covering it with one-quarter-inch of soil. Keep the ground moist but not water-logged. Johnny’s Selected Seeds has black tipped wheat, or try Silver Tip, a wheat/rye cross with huge seed heads.
Small to medium sized sunflowers are cheerful in dried arrangements, and keep long into the fall once prepared. Harvest when flowers are partially open, cutting the stem off at the length you want for arranging. Then bundle the sunflowers into groups of three, making sure the heads aren’t touching, tie with twine and hang them upside down in a cool, dark place to dry. The flowers will unfurl as they dry.
Try the pollen-less Pro Cut sunflower series; the orange, yellow peach and bi-color blooms were developed for cut flower use. Johnny’s Selected Seeds has them.
Make your own fall wreath or swag with broomcorn (Sorghum bicolor). The name is misleading – this isn’t corn – but the seed sprays of this sorghum come in bronze, burgundy, black, and cream. Harvest after the seed heads have colored up but before the stalk becomes hard and woody. Cut the stem, then hang the sprays upside down to dry. But if you want them to have a decorative arch once dried, stand them up in a vase for drying. Victory seeds has an heirloom mix.
Gardening after five 