August brings heatwaves, high temperatures and unpredictable wet weather, placing unique demands on gardens across many regions in the UK. As summer's end approaches, gardens shift: tasks change, opportunities to maximise growth narrow, and it's almost time to look ahead to autumn.
This summer holidays, you might be tending a sprawling suburban plot or nurturing a compact city balcony, either way, this guide provides clear, practical August gardening tips tailored to help you achieve a thriving garden in late summer.
Visit Boma Garden Centre in London for tailored advice, stunning displays and collections perfect for your late-summer garden.
Understanding August's Unique Garden Challenges
August often means persistent heat, increased risk of plant drought, and sudden storms. These conditions can accelerate soil drying, stress plants, and encourage pests and disease; challenges that are particularly acute for urban gardeners and those working with limited space.
- Climate Patterns: Monitor your local forecast and be ready to adapt to both hot weather, dry days and the chance of heavy rain.
- Seasonal Changes: Days start to shorten, and some crops begin winding down after their peak, while others are just getting started.
- Urban Gardening Mindset: Focus on efficiency—prioritise plant health, prepare for late planting, and make the most of garden bounty. Container gardens and balcony spaces require extra attention during this demanding month.
Fibreglass clay window boxes with perennials and bedding plants available at Boma Garden Centre
What to Plant in August
Late summer is a prime moment for succession planting and preparing for a productive autumn. At Boma Garden Centre, we specialise in helping London gardeners maximise their growing season with carefully selected varieties perfect for city conditions.
August Planting Comparison: Traditional vs. Urban Gardening
| Aspect |
Traditional Garden
|
Urban/Container Garden |
Boma Recommendation |
| Space Requirements | Large beds, direct soil planting | Containers, vertical growing, compact varieties |
Pots and planters optimised for small spaces |
| Watering Frequency | 2-3 times weekly, deep watering | Daily monitoring, more frequent watering | Quality garden equipment for efficient container watering |
| Soil Management | Ground soil amendment, mulching | Container compost refresh, drainage focus | Premium compost heap for container growing |
| Plant Selection | Full-size varieties, unlimited choice | Compact, dwarf varieties, heat-tolerant | Heat-resistant varieties from our outdoor plants collection |
| Pest Control | Natural predators, garden ecosystem | Limited beneficial insects, targeted control | Integrated pest management with resistant varieties |
| Harvest Timing | Seasonal abundance, bulk harvesting | Continuous small harvests, succession planting | Regular picking to maximise container yields |
| Climate Protection | Natural wind barriers, soil insulation | Artificial protection, container mobility | Move containers and hanging baskets to optimal positions |
| Maintenance Level | Moderate, seasonal tasks | High, daily attention required | Consider our Premium Garden Design & Planting Service for expert care |
Shrubs and Trees
August is an excellent time to plant shrubs and fruit trees. The soil is warm, which helps roots establish before winter sets in. Consider adding garden shrubs or evergreen plants for year-round structure and interest. Boma offers a variety of autumn and summer flowering shrubs and trees, including olive trees and bay trees, perfect for adding a touch of Mediterranean flair.
Flowering Plants to Sow Now
August is perfect for establishing your flower garden for next year's flower buds and garden displays:
- Biennials (e.g., foxglove, sweet William): Seed now for spectacular spring blooms.
- Hardy Annuals: Direct-sow hardy annuals like calendula, nigella, and cornflower for late season colour.
- Marigolds: These vibrant flowers thrive in the warmth of August and can add a pop of color to borders or containers. They are also excellent for deterring pests in vegetable gardens.
- Zinnias: Perfect for late summer, zinnias are heat-tolerant and come in a wide range of colors. They are ideal for both cutting gardens and container planting.
- Cosmos: Tall and elegant, cosmos are easy to grow from seed and will keep blooming well into autumn if deadheaded regularly.
- Sunflowers: Sow dwarf varieties in August for a cheerful display in small spaces or containers. Sunflowers are also great for attracting pollinators.
- Snapdragons: These hardy flowers can be planted now for a late-season bloom and will often continue into cooler autumn months.
- Plant autumn flowering bulbs like nerines and colchicums, and start ordering your spring bulbs now so that you’re ready when autumn arrives.
Top tip: As annuals like poppies, cornflowers and nigella set seeds, collect them in paper bags and store them for sowing in spring.
Digitalis purpurea 'Lucas Pink' Foxgloves
Vegetables for Succession Crops
- Lettuce: Sow heat-tolerant varieties every two weeks for continuous harvests. Leafy greens are varieties perfectly suited to late summer sowing.
- Kale: Direct seed or transplant for harvest through autumn. This hardy brassica thrives in cooler weather and is ideal for urban growing.
- Radishes: Quick-growing—plant now and harvest within three weeks. Perfect for container gardening and small spaces.
- Turnips & Spinach: Sow seeds for a fall crop; keep soil moist for good germination using quality compost to retain moisture.
- Fall Brassicas: Cabbage, broccoli, and cauliflower should be started as seedlings and transplanted outdoors for a late yield.
- Sweet Peas & Runner Beans: Sweet peas can be sown now for overwintering, leading to strong spring blooms. Runner beans, if started early in the month, can still produce a late harvest before the first frost.
Regional Recommendations for London Gardeners
London's unique microclimate within the M25 offers opportunities for extended growing seasons. Our years of horticultural experience serving the capital mean we understand exactly what works in urban conditions. Visit our London Garden Centre to see our stunning displays and get personalised advice for your specific location.
Essential August Gardening Jobs & Maintenance Tips
Consistent care keeps your garden resilient during late summer's extremes, especially crucial for balcony and container gardeners.
Watering Essentials For the Garden in August
- Water deeply in the morning to reduce evaporation in sunny weather.
- Consider setting up an efficient irrigation system to ensure your plants receive the right amount of water. Check out our range of irrigation and watering solutions at Boma to keep your garden hydrated.
- Check container plants daily; water camellias, rhododendrons, and wildlife areas like bird baths regularly.
- Feed flowering plants weekly with high-potash liquid feed like tomato feed.
Weeding, Deadheading and Pruning
- Weed regularly to reduce competition for water and nutrients.
- Deadhead faded flowers like dahlias and roses and flowered stems to extend blooms and produce further flowers, except for hip-producing varieties.
- Prune lavender, rambling roses, wisteria, and herbs like basil to maintain shape and encourage growth.
- Manage strawberry runners and prune summer-fruiting raspberries to ground level.
Lawn Care On Hot Days
- Raise mower blades to protect roots.
- Water lawns deeply but less often to encourage strong growth.
- Feed every other week with appropriate fertilisers and check for dry soil daily.
For those managing larger spaces or seeking professional results, consider our Premium Garden Design & Planting Service for comprehensive garden maintenance.
Pest & Disease Control
August gardens can see an uptick in trouble spots, particularly in the warm, humid conditions common in London's urban environment. Watch for tomato blight, powdery mildew, aphids, and slugs. City gardens often face unique challenges with limited air circulation and heat reflection from buildings. To help with this, you can:
- Use barriers and encourage beneficial insects
- Remove affected plants foliage promptly
- Choose resistant varieties from our carefully curated outdoor plant collection
- Inspect leaves top and bottom twice weekly for early signs of trouble. Container plants are particularly vulnerable and benefit from regular health checks.
Calibrachoa in a zinc metallic window box available at Boma
Harvesting and Enjoying August's Bounty
Learning when and how to harvest will maximise both yield and flavour, especially important when growing in limited urban spaces. Here are some tips.
- Timing: Pick crops like tomatoes and courgettes promptly; check daily during peak ripeness
- Tools: Use clean, sharp garden tools to avoid damaging plants
- Technique: Cut, don't tear, to avoid damaging plants and encourage continued production
Dealing with Surplus
Share with neighbours, freeze, or preserve bumper crops. Consider starting a community produce swap, perfect for building connections in London's urban gardening community.
If you have an allotment in London, you can find some allotment-specific harvesting tips for August in this handy YouTube guide from ‘That's What We Call The Good Life’.
Your Next Steps for Late Summer Success
August is a time to act: sow new crops, maintain and protect established ones, and set the stage for a bountiful autumn. Whether you're managing a small balcony or a larger urban garden, the key is understanding your specific conditions and choosing the right plants and techniques.
As you keep up with watering, planting, pruning, and harvesting, look ahead to September's tasks—like bulb planting and fall clean-up.
Ready to take your late summer garden to the next level?
Visit Boma Garden Centre to explore our extensive collections, from indoor plants perfect for bringing nature indoors to outdoor plants that thrive in London's unique conditions.
Our team brings years of horticultural experience to help you succeed, whether you're just starting your urban gardening journey or looking to refine your technique.
With London's M25 delivery service, getting the right plants and supplies for your late summer garden has never been easier, so shop now for our big summer sale.
Transform your space this August. Your autumn garden will thank you.
Frequently Asked Questions
Can I still plant tomatoes in August in London?
In most cases, it's late for seeding but possible to set out established seedlings if you have 6–8 weeks of warm weather left. Our experts can advise on the best varieties for late planting.
How often should I water during a London heatwave?
Deep watering two to three times a week is better than daily shallow watering. Always check soil moisture before watering, particularly important for container gardens.
Best way to keep slugs/snails away in urban gardens?
Hand remove, use copper barriers, and avoid watering late in the day. City gardens can be particularly prone to slug problems due to moisture retention.
Should I fertilise in August?
Feed container plants regularly, but reduce or stop fertilising perennials to avoid encouraging tender growth before frost.
