What to Plant in March UK: Best Flowers, Vegetables & Herbs for a Thriving Garden

March marks the official start of spring and is one of the busiest months in the UK gardening calendar. With longer daylight hours and gradually rising temperatures, it’s the perfect time to sow seeds, plant flowers, and start vegetables for a great growing season.

In this guide, you’ll learn:

✔️ The best flowers to plant in March in the UK
✔️ Which vegetables and herbs to sow this month
✔️ How to prepare your garden for spring planting
✔️ Tips for protecting young plants from frost

Let’s explore what to plant in March in the UK for a successful and thriving garden! ??

1. Flowers to Plant in March in the UK

March is an excellent time to plant hardy flowers that will bloom in spring and summer.

Hardy Annuals to Sow Outdoors in March

? Pansies & Violas – Bright, cheerful flowers that tolerate cooler temperatures.
? Sweet Peas – Fragrant climbers that thrive when sown early.
? Cornflowers – Pollinator-friendly flowers with vibrant blue petals.
? Nigella (Love-in-a-Mist) – Beautiful, delicate flowers that self-seed easily.

Perennials & Shrubs to Plant in March

? Lavender – Low-maintenance and great for attracting bees.
? Rudbeckia (Black-Eyed Susan) – Adds stunning golden-yellow blooms in summer.
? Echinacea (Coneflower) – Hardy, long-flowering, and perfect for wildlife gardens.
? Hardy Geraniums – Versatile and low-maintenance plants for ground cover.

Tip: Water newly planted flowers well and apply mulch around perennials to help retain moisture.

2. Vegetables to Plant in March in the UK

March is a key planting month for many hardy and early-season vegetables.

Vegetables to Sow Directly in March

? Carrots – Sow in light, well-drained soil for strong roots.
? Spinach & Lettuce – Quick-growing leafy greens ideal for early harvests.
? Potatoes – Start planting early varieties for a June harvest.
? Onions & Shallots – Plant sets directly in the ground for strong crops.
? Broad Beans – Tough, hardy legumes that handle cooler conditions.

Vegetables to Start Indoors or Under Cover

? Peppers & Chillies – Need warmth, best started indoors.
? Tomatoes – Sow seeds indoors for transplanting outdoors in May.
? Cucumbers – Require a heated propagator for best results.
? Sweetcorn – Start in pots indoors before planting out later in spring.

Tip: Protect young seedlings from frost with cloches, fleece, or polytunnels.

3. Herbs to Plant in March in the UK

March is a great month for starting herb gardens, whether in pots, raised beds, or directly in the ground.

? Basil – Needs warmth, so start indoors.
? Parsley – A hardy herb that can be grown in containers or beds.
? Coriander – Prefers cooler temperatures, making early spring ideal.
? Chives – A perennial herb that adds flavor and color to your garden.
? Thyme – Drought-resistant and perfect for borders or pots.

Tip: Sow tender herbs indoors and transplant them outdoors when the weather warms up.

4. Preparing Soil for Planting in March

For plants to thrive, soil must be well-prepared before planting.

✔️ Turn over the soil to improve aeration and drainage.
✔️ Add compost or well-rotted manure to enrich nutrients.
✔️ Mulch around perennials and shrubs to retain moisture.
✔️ Test soil pH and adjust if needed for specific plants.

Tip: Cover empty beds with black plastic or fleece to warm the soil before planting.

5. Protecting Plants from Late Frosts

March can still bring cold nights, so it’s essential to protect young plants from frost.

✔️ Use fleece or cloches to cover seedlings at night.
✔️ Move potted plants to sheltered areas if frost is expected.
✔️ Mulch around roots to insulate against temperature drops.
✔️ Water in the morning to prevent freezing overnight.

Tip: Keep an eye on the weather forecast and cover delicate plants when needed.

FAQs: What to Plant in March in the UK?

Can I plant potatoes in March in the UK?
✔️ Yes! March is the best time to plant early and maincrop potatoes for a summer harvest.

What flowers can I plant in March in the UK?
✔️ Pansies, sweet peas, cornflowers, and lavender are great choices for early planting.

Should I start tomatoes indoors in March?
✔️ Yes! Tomatoes require warmth, so they should be started indoors before transplanting outdoors in late spring.

Can I grow herbs outside in March in the UK?
✔️ Hardy herbs like parsley, chives, and thyme can be planted outdoors, but tender herbs like basil should be started indoors.

How do I protect plants from frost in March?
✔️ Use fleece, mulch, or cloches to cover young plants during cold nights.

Final Thoughts: What to Plant in March in the UK

✔️ Plant hardy flowers and perennials to brighten up your garden.
✔️ Sow vegetables like carrots, potatoes, and onions for a productive harvest.
✔️ Start tomatoes, peppers, and cucumbers indoors for transplanting later.
✔️ Plant herbs like parsley, chives, and coriander for fresh flavors.
✔️ Prepare soil and protect plants from frost to ensure strong growth.

March is one of the best months to start planting and preparing your garden for a successful growing season. A little effort now will lead to beautiful blooms and a delicious harvest later in the year! ??

What are you planting in March in the UK? Share your gardening plans in the comments!

Now you’re ready to start planting in March in the UK and enjoy a fantastic growing season! ?? Let me know if you have any questions! ?