What Seeds to Plant in March for Your Garden
March is a busy month for gardeners, signalling the transition from late winter preparation to active spring sowing. You can begin planting many seeds directly outdoors as the soil begins to warm, while others benefit from starting indoors to get a head start. This month is ideal for sowing a diverse range of vegetables, herbs, and flowers, ensuring a vibrant and productive garden throughout the warmer months.
- Direct sow hardy vegetables and root crops outdoors.
- Start tender vegetables and flowers under cover.
- Consider spring bulbs for late blooms or summer displays.
- Harden off indoor-sown seedlings before transplanting.
For those in milder regions of the UK, March offers the chance to sow more varieties directly into the ground. The key is to assess soil conditions; if it's still waterlogged or very cold, it's wiser to wait or continue using protective covers. Conversely, areas experiencing early warmth can take advantage of sowing directly, avoiding the need for later transplanting. This approach is particularly beneficial for crops that dislike root disturbance, such as carrots and radishes.
Starting seeds indoors remains a crucial strategy, especially for less hardy varieties or if your garden experiences unpredictable spring weather. This method allows you to control the environment, providing consistent warmth and light for germination. Once seedlings have developed a strong root system and the risk of frost has significantly diminished, they can be gradually acclimatised to outdoor conditions through a process called hardening off. This critical step prepares them for the rigours of garden life, preventing shock and promoting healthy growth.
Hardy Vegetables for Direct Sowing
Several robust vegetable seeds can be sown directly into the soil in March. These are varieties that can withstand cooler temperatures and are less susceptible to damage from late frosts. Consider sowing peas and broad beans, which are excellent nitrogen fixers and can provide an early crop. Root vegetables like carrots, parsnips, and beetroot can also be sown directly. For the best results, prepare the soil by clearing any weeds and breaking up any large clods of earth to provide a fine tilth. Sow seeds at the depth recommended on the packet, typically 2-3 times their own width, and keep the soil consistently moist.
Tender Vegetables and Herbs - Start Indoors
For many popular vegetables and herbs, March is the prime time to start them off indoors or in a greenhouse. Tomatoes, peppers, and aubergines require a longer growing season and benefit significantly from an early start under cover. Sow seeds in small pots or trays filled with a good quality seed compost. Ensure they receive adequate light and warmth, often requiring temperatures of 18-21°C for germination. Once seedlings appear and have developed their first true leaves, they can be pricked out and repotted into individual containers or larger modules. This is also a good time to sow basil, parsley, and chives indoors; these herbs will provide fresh flavour throughout the summer and autumn.
Flowers for Early Blooms and Summer Colour
The range of flowers you can plant in March is extensive, catering to both immediate garden colour and future displays. For early blooms, consider sowing hardy annuals such as calendula, cornflowers, and nasturtiums directly into prepared beds. These are often straightforward to grow and will flower relatively quickly. If you wish to get a head start on more tender annuals like zinnias, cosmos, and marigolds, start them indoors now. These will be ready to plant out after the last frost, providing a succession of vibrant colours. Remember to check specific planting times for your region, as microclimates can affect when it's safe to sow outdoors.
March sowing offers a dual benefit: securing early harvests and laying the groundwork for a spectacular summer display.
Spring Bulbs to Plant Now
While many spring bulbs are planted in autumn, March is still a viable time to plant certain types, particularly those that bloom later in spring or early summer. Consider planting summer-flowering bulbs such as dahlias, gladioli, and lilies. These bulbs thrive in warmer soil and will require protection from any late frosts. Ensure they are planted in well-drained soil, at the correct depth, and in a position that receives adequate sunlight. Planting now will allow them to establish a root system and begin growth, ready to provide a stunning visual impact when they reach their full flowering potential.
Choosing the Right Seeds for March Conditions
Selecting the correct seeds for planting in March depends heavily on your local climate and the specific conditions in your garden. The UK's weather can be notoriously variable in March, with potential for late frosts, cold snaps, and periods of welcome sunshine. Understanding which plants are more tolerant of these conditions is crucial for success. Hardy varieties are your best bet for direct sowing, offering resilience against unpredictable weather.
Assessing Soil Temperature and Condition
The most significant factor determining what you can plant directly outdoors is soil temperature. Most vegetable seeds will not germinate effectively in soil that is too cold, often below 5-7°C. For March planting, aim for soil that has warmed up sufficiently. You can check this using a soil thermometer or by observing how quickly the ground dries after rain. If the soil is heavy clay and remains waterlogged, it will need time to drain and warm up. Adding organic matter, such as compost, can improve drainage and soil structure, making it more receptive to sowing earlier in the season.
Direct Sowing vs. Starting Indoors
The decision between sowing seeds directly into the garden or starting them under cover (indoors, greenhouse, or cold frame) is a fundamental one for March. Direct sowing is simpler and avoids transplant shock but is only suitable for robust plants or when soil conditions are favourable. Hardy vegetables like spinach, rocket, and radishes can often be sown directly, as can certain hardy annual flowers. For crops that require warmer temperatures or a longer growing season, such as tomatoes, peppers, and many common herbs like basil, starting them indoors is essential. This gives them a vital head start, ensuring they develop sufficiently to produce a harvest or bloom later in the year.
A gardener's patience in March can yield bountiful rewards, with careful observation and selection paving the way for a thriving plot.
Hardy Annuals and Biennials
March is an excellent time to sow hardy annuals directly into the ground. These plants are bred to withstand some frost and will grow quickly once conditions are right. Examples include poppies, larkspur, and gypsophila. These will bloom from late spring through summer. For biennials, which complete their life cycle over two years, March sowing is often the first step to establishing plants that will flower next year. Examples include wallflowers and foxgloves, which will grow foliage this year and flower profusely the next, providing structure and colour.
Considerations for Container Gardening
If you are gardening in containers or on a balcony, your planting schedule might differ slightly. Container soil tends to warm up and dry out faster than garden soil. This can be advantageous in early spring, allowing you to sow seeds like lettuce, spinach, and spring onions a little earlier. However, it also means containers can be more susceptible to frost, so keep tender seedlings protected. Choosing compact or dwarf varieties is also a wise strategy for container gardening, ensuring plants have enough space to thrive.
Selecting the right seed variety and sowing method is paramount for success in March's variable climate.
A Practical Guide to Planting Seeds in March
Successfully planting seeds in March involves more than just scattering them in the soil; it requires careful preparation and attention to detail. Whether you are sowing directly outdoors or starting seeds under protection, following good practices will maximise your chances of germination and healthy plant development.
Preparing Your Seed Beds
Before sowing any seeds outdoors, it's vital to prepare your garden beds. Remove any weeds, debris, or old plant matter from the previous season. Digging the soil over to a depth of about 20-25 cm will help to break up compacted earth and improve aeration. Rake the surface to create a fine, level tilth, removing any stones or large clods. This fine surface is essential for small seeds, ensuring they are covered evenly and can establish good contact with the soil for germination.
Sowing Techniques for Success
When sowing seeds, consider the size of the seed and its specific requirements. Tiny seeds, such as those of lettuce or poppy, can be sown very shallowly, sometimes just scattered on the surface and lightly pressed in. Larger seeds, like peas or beans, need to be sown deeper, typically 2.5-5 cm down, to protect them from birds and ensure they have enough energy reserves to reach the surface. Always follow the packet instructions for sowing depth and spacing. For rows, a trowel or a stick can create a straight furrow, while broadcasting involves scattering seeds over a wider area, often for flowers or leafy greens.
Improve germination rates by pre-soaking larger seeds like peas or beans for a few hours in lukewarm water the night before sowing.
Germination and Early Care
Once seeds are sown, consistent moisture is key for germination. Use a watering can with a fine rose attachment to water gently, avoiding dislodging the seeds. For seeds started indoors, ensure they are kept in a warm location, out of direct, harsh sunlight which can scorch young seedlings. A propagator or a warm windowsill is ideal. Monitor the soil moisture regularly; it should be kept consistently damp but not waterlogged, as this can lead to rot or fungal diseases like damping off.
Hardening Off Seedlings
For any seeds started indoors that you intend to plant out into the garden, the process of hardening off is non-negotiable. This gradually acclimatises tender young plants to outdoor conditions such as lower temperatures, wind, and stronger sunlight. Start by moving them to a sheltered outdoor spot for a few hours each day, bringing them back inside at night. Over a week or two, gradually increase the time they spend outdoors and expose them to more direct light. This process is critical for reducing transplant shock and ensuring survival.
Paying attention to the nuances of seed preparation and seedling care is what separates a struggling garden from a flourishing one.
What to Plant in March: A Comprehensive List
March is a month of transition, offering a broad spectrum of planting opportunities across vegetables, herbs, and flowers. The specific success of each seed depends on your local climate within the UK, but this list covers commonly recommended varieties for sowing during this period.
Vegetable Seeds for March
Many vegetables can be sown directly into the ground in March, provided the soil has warmed sufficiently and is not waterlogged. Others are best started indoors or in a protected environment. Those suitable for direct sowing include: broad beans, peas, spinach, lettuce (hardy varieties), rocket, radishes, carrots, parsnips, beetroot, and spring onions. For indoor sowing, focus on: tomatoes, peppers, aubergines, cucumbers, courgettes, and early leeks.
Herb Seeds for March
Fresh herbs elevate any dish, and March is a key month for their propagation. Directly sow hardy herbs like parsley, chives, and dill outdoors when the soil becomes workable. For less hardy varieties or those that need a longer growing season, start them indoors. This includes basil, coriander, and thyme. Mint and rosemary are often best propagated from cuttings, but seeds can be sown indoors for these too.
Flower Seeds for March
Spring and summer flowering plants can be initiated in March. Hardy annuals like calendula, cornflowers, poppies, and nasturtiums can be sown directly into beds, adding colour and attracting beneficial insects. Tender annuals such as zinnias, cosmos, marigolds, and petunias should be started indoors or in a greenhouse to get a head start, ready for planting out after the risk of frost has passed. Perennials and biennials like foxgloves, delphiniums, and aquilegias can also be sown indoors now.
Bulbs for Late Spring/Summer Display
While autumn planting is typical for many bulbs, March is suitable for introducing summer-flowering varieties to your garden. Plant dahlias, gladioli, lilies, begonias, and cannas directly into well-drained soil. Ensure they are at the correct depth to protect them from frost and provide them with ample sunlight. These will develop over the spring months, ready to provide spectacular blooms when many spring flowers are fading.
What to Plant Now: A Summary Table
| Category | Direct Sow Outdoors | Start Indoors/Protected |
|---|---|---|
| Vegetables | Broad Beans, Peas, Spinach, Lettuce, Rocket, Radishes, Carrots, Parsnips, Beetroot, Spring Onions | Tomatoes, Peppers, Aubergines, Cucumbers, Courgettes, Early Leeks |
| Herbs | Parsley, Chives, Dill | Basil, Coriander, Thyme |
| Flowers | Calendula, Cornflowers, Poppies, Nasturtiums | Zinnias, Cosmos, Marigolds, Petunias, Foxgloves, Delphiniums |
| Bulbs | Dahlias, Gladioli, Lilies, Begonias, Cannas (for summer bloom) | N/A (typically planted directly outdoors) |
The success of your March planting hinges on understanding the specific needs of each plant and the prevailing weather conditions.