These Are the Fastest Growing Plants You Can Still Grow This Season

Green Beans

Green beans are a delicious addition to any garden, because they can be succession grown, Gail Pabst, gardening expert at the National Garden Bureau, explains. This means you can plant them a few times throughout the summer to get fresh beans up until frost. Some beans, such as the Mascotte bean, grow quickly, with only 50 days from sowing to harvest.

Bush beans also grow compactly and do not need a structure to grow on. “They do well in containers and in gardens,” Pabst says. Pole beans grow as climbing vines and require staking. They usually take a few additional days to produce compared to bush beans.

Summer Squash

Many squashes are produced in a very short time span, anywhere from 35-50 days. “One bonus for planting later in the season is that you have less trouble with squash vine borer, a moth that kills squash plants early in the season,” Pabst says.

If you live in a warmer climate, you can plant your first crop in mid-March so it will harvest before the adult moths appear in May. If you want a second harvest or you missed the first window, you can also plant later in the season when the moths have moved to find a new place to lay their eggs.

If you can find them, Pabst recommends the fast-growing varieties Bossa Nova zucchini, Eight Ball squash, and Gold Rush squash.

Mandevilla

Mandevilla, also known as rocktrumpet, is a genus of tropical vines that produce large, trumpet-shaped flowers from spring through fall. “You’ll find cultivars with red, white, pink, or yellow flowers, all of which are fragrant and favored by hummingbirds and butterflies,” says Halleck.

To encourage late-season growth in a container, hanging basket, or garden bed with trellis support, pick a sunny location (Hallecky says plants can tolerate some late afternoon shade). If your plants aren’t flowering, they probably need more sun.

Salvia (Garden Sage)

Garden sage—a relative of the culinary herb—produces velvety foliage and tubular blossoms in hues of pink, purple, blue, red, and white. Most species and cultivars of salvias, even perennial salvias, are fast growers and bloom continuously.

Halleck recommends annual salvia cultivars for popping in some quick color to pots or entryway beds, and perennial salvia species and cultivars to attract pollinators in sun gardens.

Coleus

Coleus scutellarioides and its varieties and cultivars are workhorses of the garden and container plantings, Halleck says, providing both color and structure all season long.

There are many foliage colors and combinations to choose from, as well as types for both shady and sunny conditions. Plants are fast growing and prefer consistently moist (but not wet) conditions. “Coleus may wilt when dry or conditions are very hot, but will quickly perk back up once watered,” says Halleck.

Cucumbers

Like beans, you can find vining and bush varieties of cucumbers. The fastest-growing varieties, Pabst says, are the Parisian gherkin, Pick a Bushel, and Saladmore, all of which yield a harvest within around 50 days. 

An important tip from Pabst: Don’t let the fruit get too large, or they will taste bitter. For gourmet mini cucumbers and pickling, pick the fruit when it's between 3 to 4 inches long. For snacking and enjoying fresh in salads, pick the cucumbers when they’re 6 to 8 inches in size.

Basil

Along with enhancing your recipes, herbs make beautiful ornamentals. Basil, Halleck says, loves the heat and grows faster during the warm summer months. You can tuck it into mixed planters or garden beds in a sunny location with regular watering. 

Keep in mind basil doesn’t like cool, wet soil, so if you’re in a cooler climate, plants will grow more slowly, and you’ll want to water them less. Halleck recommends letting some of your basil go to flower, “as the blooms are both beautiful and beneficial for pollinators.”

Greens

Greens are another quick crop you can grow (and harvest) anytime. Fully-grown greens are great for salads and stir fries, or you can harvest them much earlier and use them as baby greens.

In the warmer summer months, greens grow well in partial or full shade (but be sure to check the requirements for the specific plant you choose). Pabst recommends varieties that are slow to bolt (or go to seed), such as 'Sandy' lettuce and bok choy.

Plectranthus 'Velvet Elvis'

These vigorous plants produce a bounty of big, purple blooms with velvety foliage in late summer and fall. They’re great for pots and sparse garden sections that don’t get great sun, as Halleck says these lavender beauties thrive in the shade. “Plants prefer loose humus-rich soil or potting mix that stays relatively moist but can tolerate some drying,” she adds.

Marigolds

Looking for fall-inspired flowers? Pabst recommends planting marigold seeds in your garden or container. Some varieties, such as Janie Gold, bloom in six weeks from planting the seeds.

Though their coppery color reminds us of fall, marigolds can withstand the hottest temperatures of summer, and they grow quickly in full sun.