What to do in the garden in March

1. Plant summer bulbs, such as Dahlia and Lily
2. More pruning this month: Roses, Buddleia, Cornus, Hydrangea and more
3. Plant snowdrops in the green for next year's display
4. Prepare the veg plot
5. Start to sow hardier seeds and half-hardy annuals under glass

March and April is summer bulb planting time ideal for as Dahlia and Lilies. Planting as bulbs or tubers is cheaper than buying pot-grown plants later in the year. 

If you buy Dahlias as tubers, you need to plant about 6 weeks before the last expected frosts. This is because Dahlias are not frost hardy (explanation of frost hardy) and frost will damage the new top growth.

It takes about 6 weeks for the new growth to come through, which is the reason for the time delay. If you get caught out, cloche them. If your growing conditions are not ideal, such as colder or wetter, it is better to start Dahlias in containers under glass and bring out to harden off in May. More tips about How to Grow Dahlias.

Where ever you plant Dahlia, the pointy end goes up. If you look at the image, you can see where last year's stem was, and this goes upright, and it's planted as per the image.

 The image above centre is Lilium Regale. March is the right time to plant lily bulbs. Pick a good-sized pot and fill with suitable compost, plant 3 bulbs per pot, and cover with more compost.

Keep the bulbs in a sheltered spot or in the greenhouse until established. The pots are ideal for placing on the patio to enjoy the scent or filling up gaps in the borders. More about growing lilies and images of different types of Lilies.

In March, you can tidy up perennials and cut them back before the new growth gets too advanced. Once the plant has started regrowing in earnest, it can be difficult to cut back without damaging the new growth.

In the image, the Sedum has had all the old growth removed. 

This is a good time to assess the performance of spring bulbs, especially daffodils. If you have a clump of daffodils which are blind, that is to say, without flowers, mark them with a stick for attention. Once the foliage has gone over, lift the clump and check them. If they are congested, plant back, having first separated the bulbs and plant further apart. You can also try planting deeper if they have failed to flower.

As the early daffodils finish flowering, dead head them but it's important to leave the foliage in situ until it has died back. This feeds the bulb for next year, plus you can give the fading bulbs a feed as well. 

Another common cause of blind bulbs is if they are planted too shallow. Ensure when re planting the clump it is at least 3x the depth of the bulb. Check out Why don't spring bulbs flower? 

Many plants and shrubs are ideal grown in containers and on a permanent basis. Over time, the compost can become depleted. One way to remedy this is to apply a feed, and the other is to topdress the container in the spring. To do this, remove the top 5-7cms of compost from the container and top it up with fresh compost, which will improve the soil. All containers are prone to drying out more quickly, applying a mulch may help to reduce water loss.

No need to waste the compost you remove. Spent compost makes an ideal mulch and is useful for topping up soil levels in borders.

March is the month when planting gets under way and before planting, it is worth spending time to improve the soil and raise yields. Most vegetables are hungry feeders and it's a good idea to enrich the soil with organic matter such as well rotted manure, chicken pellets, or compost. Digging the soil and mixing in organic material will break up the soil, ensuring it is not compacted, and prepare it for the growing season. However, if it is very wet, or has been a wet winter, it is more important to keep off the soil so it doesn't get compacted.  Many crops such as salads and carrots like a fine soil and stones are a hindrance. Raking the plot to render the soil finer makes it easier to plant into and creates a better growing medium, as in the image.  

Whether you are growing your vegetables from seed or small veg plants, deciding when to plant out in the veg plot depends on the veg, the weather, and your plot. 

The hardiest of the Bean family are Broad beans, which means they can be planted out first. In March, you can sow outside if the soil is warm enough, but you will need to protect new growth from a heavy frost or snow by a fleece or cloche. An alternative if you have a conservatory, greenhouse, or cold frame is to sow seed and under glass so you have sturdy plants to put into the veg plot later in the Spring. In March it is best to plant outside only hardy vegetables.

  The same applies if you are buying small vegetable plants. They will need protection from the worst of the weather. Small plug plants are good value, but it is as well to bear in mind the garden retailers/grows have them in ideal conditions protected from the weather. After purchasing, you will need to try to do the same.

All Beans like a long root run are best germinated into root trainers or loo rolls holders. Sow the seed nearer the top of the holder so the roots can reach down. The same is true if you are sowing sweet peas. Beans need no attention whilst growing on other than to ensure light levels are good so that plants do not get spindly. Water carefully if in loo rolls holders, only in the centre, try not to water the cardboard holder as it will disintegrate.

If your plot is exposed/subject to frosts and cold winds even with cloches and protection available, it is best to delay outside sowing of French beans, cucumbers and squashes until later April/May. You can sow these under glass and start off young plants, but for outside sowing or planting out it is better to wait for later in the season.