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What to Plant in August UK

What to Plant in August UK

What to Plant in August UK - Seeds for Late Summer Success

August is a strategic and valuable month in the UK gardening calendar - a time to enjoy a garden in bloom, while also planning for the season ahead. The soil is warm, the light is good and there’s still time for Autumn crops to get established before winter frosts arrive.

Whether you’ve got an allotment, a few containers, or a sunny windowsill, August is packed with growing potential. From root veg for your Christmas dinner, to wildflowers for the pollinators, here’s what you can sow in August in the UK to keep things growing through Autumn and beyond.

What to Sow in August - A Quick Overview

Here are some quick ideas for seeds you can plant this month:

Vegetables:

Lettuce, beetroot, cauliflower, carrots, spring onions, radish

Flowers:

Nigella, cornflowers, poppies, pansies, forget-me-nots

Wildflowers:

Foxgloves and other UK natives like Soapwort (for bees, butterflies and birds)

Why August is a Good Time to Sow Seeds

August is a growing sweet spot, with warm soil that helps seeds germinate quickly and cooler weather ahead that many crops prefer. It’s also a great time to succession sow, filling gaps left by earlier harvests and making the most of the remaining light and warmth.

As we move into Autumn, leafy crops like lettuce and rocket grow more steadily, focusing on leaf production rather than bolting (trying to flower and produce seeds). That means tender, tasty harvests.

Vegetables to Sow in August (UK)

August vegetable planting is all about timing - you want plants that'll germinate before winter sets in. Many of these are ideal for small gardens or containers, and they don’t mind the shorter days ahead.

Quick-Growing Leafy Greens

  • Lettuces like Iceberg and Little Gem germinate quickly and handle the first frosts well. Cut-and-come-again varieties give quick results and are great for busy kids to nibble on

  • Salad Rocket, with its peppery leaves, seems to be almost indestructible once established. We’ve seen it survive plenty of winters if it’s got a bit of protection!

  • Fine Curled Cress is a great indoor growing project for kids

  • Mizuna and Italian leaves, like Radicchio, add interesting flavours to late-season salads

Root Vegetables for Autumn and Storage

  • Beetroot Detroit and Carrot Nantes can be sown now for smaller autumn harvests

  • Radish French Breakfast grows quickly and handles cooler nights well

  • Spring Onion Welsh Red sown now gives you crisp, flavourful stems by late autumn

Hardier Veg for Winter Growth

  • Cauliflower All Year Round lives up to its name - sow in August for early heads in spring

  • Dwarf French Bean or Garden Pea Early Onward can still be sown in early August in warmer parts of the UK, ideal for a late flush of pods before frost

You can find all of these (and much more!) in our Grow Your Own Vegetable Seed Pack - with 21 different varieties and over 1,700 seeds in 4 themed collections: Veg Patch, Spicy Salsa, Salad Bowl, and Peas & Beans. Each seed is carefully selected for UK conditions and comes with easy-to-follow instructions for a year-round supply of delicious crops.

Flowers to Plant in August

Some flowers can be sown in August to set you up for spectacular spring displays, while others will bring colour before the first frosts. These are great options for beds, borders and containers:

  • Pansy – A classic for winter pots, pansies sown in August can bloom right through into spring in milder areas.
  • Forget-Me-Not – A reliable spring favourite that blooms early next year.
  • Cornflower – Sown now, it establishes well and flowers earlier next summer.
  • Poppy – Scatter now for a naturalised look and blooms next spring.
  • Foxglove – Sow now for flowering the following summer. Perfect for shady spots.

Sweet Peas - Get A Head Start on Summer Scent

Sow sweet peas in August for earlier, stronger blooms next year. If you tuck them in a sheltered spot or cold frame, they’ll develop strong root systems that help extend their growing season.

All Pronto Seed varieties, including Bijou Mix, Royal Blue, Royal White, Royal Maroon, Harlequin Mix and Striped Ripple Mix, can be sown now into deep pots or root trainers. Plant out in spring once the risk of frost has passed.

Our Grow Your Own Flower Seed Pack is an easy way for first-time growers to get colourful blooms at home. It contains 24 varieties and over 3,100 seeds across four curated collections: Baskets & Containers, Butterfly & Bee, Easy Grow and Sweet Pea. Perfect for pollinator-friendly colour in borders and planters.

Wildflowers and Pollinator Plants

Some wildflowers need a period of cold to break dormancy and trigger germination, so a native wildflower mix sown in August will establish slowly over winter and burst into life next Spring.

Look out for mixes containing varieties designed to support bees and butterflies, like:

  • Yarrow, Scented Stocks, Borage and Common Poppy

Our Wildflower Seed Shaker Twin Pack includes a classic mix of 20+ varieties and covers an area of 2 x 50m², ideal for beds, borders, or meadow-style planting. 

Make Seed Sowing Simple with Coir Potting Soil Discs

If you're sowing in trays, pots, or windowsill planters, Pronto Seed coir potting soil discs are a practical alternative to bagged compost, especially if you're short on storage space.

Made from natural coconut fibre, each dry 10cm disc expands into 1.3 litres of soft potting soil that's perfect for seeds or potting on young plants.

There are no plastic bags to dispose of; everything is packaged in cardboard. Just place a dry disc in a tray, add water and watch as it expands.

  • Gardeners love them because they’re:
  • Compact and easy to store - great for flats or small spaces
  • Peat-free and eco-friendly
  • Less messy than bagged compost - ideal for sowing indoors or on the kitchen table
  • Good for healthy root systems

Practical Tips for August Sowing

Soil Preparation

August soil can be dry and hard from the summer heat. If you’re sowing outdoors, water thoroughly the day before sowing, then rake to create a fine surface. Use grow bags or containers if space is limited. Seeds need good soil contact to germinate well. 

Watering

Keep newly sown areas consistently moist but not waterlogged. Morning watering is best; it gives plants time to dry before the evening, reducing the risk of fungal problems.

Protection

Pigeons and other birds love fresh seedlings. You can protect sowings with old net curtains or make DIY cloches from plastic bottles. Slug patrols become more important as autumn moisture returns, and a night-time torch hunt avoids using chemicals that can affect other wildlife.

Succession Planning

Sow little and often, rather than in one large batch. This gives you a steady supply of fresh vegetables, instead of a glut followed by nothing. 

Looking Ahead

While Spring tends to steal the growing spotlight, August is just as important. These late summer sowings will keep your garden productive during the hungry gap of winter and set you up for fresh flavours and colour when you need it most.

And remember, growing your own flowers and vegetables isn’t about being ‘social media’ perfect. A few seeds sown in an old plant pot will reward you with food that tastes 100 times better than a supermarket equivalent - and there’s nothing like the satisfaction of picking it yourself!

What will you sow this August?