Keeping Your Annuals Going into Autumn
Begonias, Cincinnati Zoo & Botanical Gardens, Late August 2025 (John Morgan)
As August winds down here in the Mid-Ohio Valley, it can feel like the best of the summer color is behind us. It isn’t. Those petunias, begonias, vinca, impatiens, marigolds, and coleus still have weeks of good looks left if we give them a little extra attention.
We’ve grown these plants in our Mason greenhouses for a long time. We know they can carry color right up to a typical first frost in late October when they’re watered, fed, and tidied up. A few simple habits make the difference between plants that look tired and plants that still look like they belong in the garden.
The Basics
Water consistently, especially in containers and hanging baskets. Even as nights cool a bit, days can still be warm and dry. Aim for a thorough soak rather than frequent light sprinkles, and water in the morning when you can so foliage has time to dry.
These plants have been working hard all summer. A regular dose of liquid fertilizer, like Jack’s Classic, (every week or two, following the label) gives them the boost they need for another flush of growth and flowers.
Deadhead spent blooms. Removing old flowers keeps plants from putting energy into seed and encourages more color. While you’re at it, pinch or snip any long, bare stems so the plant fills back in.
Take a quick look for pests or tired leaves as you go. Catching a problem early is easier than trying to revive a plant that’s already declining.
Plant-by-plant Notes
Mixed Landscape Planting, Cincinnati Zoo & Botanical Garden, Late August 2025 (John Morgan)
Petunias often get leggy in the heat. Don’t be shy about cutting them back by about a third. They bounce back with new growth and more flowers. Keep deadheading (include a bit of stem, not just the flower) and keep feeding them. They can bloom until frost.
Begonias like even moisture but not soggy soil. Many types don’t need much deadheading. Keep them from drying out completely, especially in pots, and they’ll hold their color well into cooler weather.
Vinca (the annual kind) is one of the most reliable late-season performers. It handles heat and some dryness better than many annuals, but it still looks better with regular water. These plants typically keep blooming until frost with very little fuss.
Impatiens want consistent moisture and usually prefer some shade. Don’t let them wilt repeatedly. Newer types (including many New Guinea and SunPatiens-style plants) are more sun-tolerant, so check what you have. Keep them watered and they’ll continue to fill in.
Marigolds are tough and heat-loving. Regular deadheading is the main job—pinch or snip the old blooms and they’ll keep producing. They’re also good for pollinators and hold up well until a hard frost.
Coleus is grown for foliage, so pinch off any flower spikes that appear. That keeps the plant focused on those colorful leaves. Many newer varieties take more sun than the old shade-only types. Water them well; they wilt quickly when dry. You can even take cuttings if you want to try overwintering a favorite indoors.
A Little Extra Time
Watch the forecast as we move through September and into October. A sheet or light cover on a chilly night can protect plants from an early light frost and buy you more color. Most of these annuals will keep going until a harder freeze.
There’s still plenty of season left. A little watering, feeding, and tidying now lets you enjoy the plants you already have instead of feeling like summer ended too soon.
Stop by your local Bob’s Market in Mason, Gallipolis, or Belpre if you have questions or need a few supplies. We’re glad to help you get the most from what’s already growing.
The fall gardening season is just around the corner and we’re working on growing a wide selection of fall plants for both your landscape and vegetable garden. From mums with the beautiful mounds of color to pansies that can be planted in fall and will survive through the winter to give you more color in the early spring, get ready to start planning your cozy season landscape with Bob’s.
Sun-Patiens, Cincinnati Zoo & Botanical Gardens, Late August 2025 (John Morgan)
