What Do I Need to Do in the Garden in March?
It’s not just our interiors that can benefit from a spring clean as the seasons change – it will do wonders for your garden, too
Plants that grow best in acidic soil, such as rhododendrons and camellias, need feeding with ericaceous feed, especially if your soil is neutral or alkaline. You can also give the plants a dose of sequestered iron to prevent the leaves from turning yellow.
If you need to trim any pine trees in your garden or they have shed a load of leaves, don’t burn them, but use as a mulch around the base of any acid-loving plant to help acidify the soil – this is really great for blueberries.
If you’ve left last year’s flower heads on your hydrangeas to overwinter, now’s the time to deadhead. Don’t remove the stems with a flower head on top, but snip old stems just above the top healthiest bud and prune out weaker shoots from the base of the plant.
To keep older plants looking healthy, cut out thick, woody stems from the base to keep the plant compact.
This is the ideal time to plant herbaceous perennials, which are starting to come into garden centres in March, or showing signs of new life again in borders after dying back in winter. I get so excited at this time of year seeing all the fresh new growth and healthy plants emerging.
If any of your perennials need dividing and moving, do it now to improve their vigour and you will create so many lovely new plants for your garden. Plant in odd numbers for a better effect, as just one of something – unless a specimen – always looks lost in a border.
Your grass will start growing now, so rake up any fallen leaves and moss before you give it the first cut of the season. Before you do cut, pull a stiff brush over the lawn to encourage the blades of grass to stand up. Set your mower high, at about 2.5cm, until the grass grows more, when you will need to lower the setting.
It’s also a good idea to trim the edges of the lawn with a half-moon edging tool to make your borders look neater. Using a plank as a guide will ensure a straighter edge: lay it where you want your line to be, then stand on it as you push down your edging tool along its length.
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I spend a lot of my time chest deep in ponds and, even in waders, it isn’t that warm at this time of year. However, if you haven’t already started to clear weed and cut back, as well as repot your aquatic plants, then be brave and get in!
First, tackle the plants: repot if you can see the roots bursting out of the baskets, and top dress with a layer of shingle. You should also remove any dead or decaying leaves; some stems will just come away without cutting at the base.
Despite the cold temperature, there will still be a great deal of blanket weed to remove, but be careful, as it can attach to rocks and stones as you pull. Also leave it on the side of the pond before disposing of it, so as to allow any creatures to get back into the water.
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Keep you greenhouse well ventilated, especially on warmer days. It’s surprising how quickly the temperature inside can rise, even if the sun is only out for a short time. Plants don’t like extremes of heat or cold, so good ventilation is key and will also keep the bugs down.
Also make sure the glass is clean, to give maximum light to any seedlings. The cleaner the glass, the sturdier the plants will be.
To grow a good crop of fruit, add potash now. Although many fertilisers contain potash, add extra if you can. If you’ve mulched around the fruit trees or bushes, move that away before applying the potash. If the soil is dry, water the potash in well as it will have no effect if it can’t reach the roots. Apply new mulch over the top if needed.
You can also spray apple and pears now against scab, especially while the flower buds are tight. You can repeat this now and again when they begin to open.
Sow hardy herbs outside: these include dill, chives, fennel, marjoram, coriander and parsley. Don’t be afraid to mix herbs in the borders with other perennials to add interest, or plant them in pots and containers for table displays.
You can also create a stunning small herb garden parterre (a formally patterned garden) and edge the beds with rows of chives – but make sure you plant mint in containers or it will take over and run everywhere. Be careful, too, of borage, unless you want your garden filled with it! It has a pretty blue flower, but is a real thug and will invade everything, even working its way into stonework.
If your daffodils are beginning to fade and look a mess, you can deadhead them, but leave the foliage if you can, as that’s where all the energy is stored for seed production. I get a bit of garden twine and tie the leaves together carefully, top and bottom, so they don’t look too messy. This isn’t necessary in large areas of grass, but it does look neater in the borders.
If you’re planning to grow asparagus, this is the month to start. It’s easy to cultivate and thrives in well-drained soil. The plants don’t grow well from seed, so one-year-old crowns are best.
Start by digging a shallow trench, around 25cm deep and 30cm wide. Add compost and a good handful of bonemeal. Place the crowns carefully 45cm apart, spreading the roots out. Sieve the soil and liberally cover the crowns, so that emerging buds are just below the level of the soil. As they have shallow roots, don’t use a hoe when weeding.
Are you planning to get out into the garden this March? Share any tips and photos in the Comments.