April Gardening Tips

Spring is now fully underway and for us gardeners, it is an exciting month as the gardens are starting to look green and vibrant once again. The days are getting warmer and longer, although not without the odd dramatic April shower to keep us on our toes. The sound of lawnmowers coming out of their winter hibernation reminds us that we will be busy in the gardens once more, keeping everything looking healthy. This month brings opportunities to either introduce new plants and ideas to our green spaces or maintain what already enables us to connect with nature.

Check for early signs of pests – The better weather brings out the pests and we need to be checking our plants and trees for any early signs of colonies that could be moving in. As they say, prevention is better than cure. Aphids are a common garden visitor and will be eyeing up our roses and perennials. Rub or hose off aphids when you see them and try to avoid pesticide sprays if you can to support friendly and beneficial visitors. Early action prevents any colonies from building up.
Trim winter flowering heathers – If you didn’t do this earlier in the year, now is a good time as the flowering stems will most likely be spent and looking a bit tatty. Remove the old stems completely to show off the more attractive new growth.
Plant evergreen hedging plants – April is a great month to plant evergreen hedging plants as there is less chance of them being damaged by the cold winter winds. The warmer weather and rain showers will allow them to establish well too. At Nicholsons, we supply a wide range of hedging from old favourites such as yew (Taxus baccata) to box alternatives such as Euonymus japonicus ‘Green Spire’ and Japanese holly (Ilex crenata).
Tie in climbing roses and ramblers – Any loose or new shoots will need tying in and training horizontally. This causes the flow of sap to be restricted, resulting in more side shoots developing along the whole length of the main stems, producing more flowers. If left to grow vertically, all the flowers will grow at the tips of the stems, making them less visible.
Plant and sow herbs – By now, most herbs can be sown outside and any sown earlier can be planted out from the end of the month, after hardening off in a cold frame. Many young herb plants are now available to buy.
Plant out sweet peas – A perfect choice to grow inside an obelisk. Although sweet peas should have been sown earlier, it is still possible to get some flowers in late summer or autumn if you sow them now. Towards the end of the month, it will be safe to plant out sweet peas that were sown in autumn as long as they have been hardened off first for one or two weeks (see the March tips explaining what this means).
Top up grit and gravel for your Mediterranean garden – Topping up any grit or gravel shifted by the winter weather will smarten up the area before the plants get going and set them off perfectly when they are at their best.
Finish dividing summer flowering perennials – April is the latest month for lifting and dividing if you want them to flower in the summer and autumn. Where possible, always revitalise the soil with well-rotted farmyard manure or garden compost before replanting perennials. Water in well after planting, particularly if the weather is dry. I have just divided my Sedums (now called Hylotelephium), which have established very well in our recent wet weather.
Sow annual grasses – Grasses can bring contrast in a garden when planted next to broad-leaf plants. A more ‘naturalistic’ look is achieved within the border, with delicate foliage and attractive seedbeds. Try hare’s tail grass (Lagurus ovatus) or squirrel tail grass (Hordeum jubatum), which can all be sown outside from now on. You can sow them in drifts, similar to annual flowers, or sow them in drills so you can identify them from weed grasses when they germinate.
Sow tomatoes – Sow your tomatoes now in order to plant outdoors in early June. Sow the seeds thinly in trays or small pots containing seed compost and cover them with vermiculite. When the seeds germinate and are large enough, either prick out into trays or into small pots. There are many tomato varieties to choose from and it comes down to a matter of taste as to which ones you grow. You could try trailing tomatoes which you can grow in hanging baskets for something a bit different.