WELL what a dreadful start to spring, cold and grey and now back to the sub zero temperatures that have done so much damage over the winter months. The number one gardening job this month is to assess what plants have been hit the worst, see what damage has been done and decide what we can do about it. Obviously, this will depend on your area, but with the sustained minus temperatures, we’ve seen plenty of plants that have been killed outright with no hope of regrowth. The advice for most plants is to be patient, wait for another month or two when it will be more obvious as to what is alive and what is dead. Don’t automatically think that everything is dead because it is browned off by frost. Many plants are tougher than you think and may well regrow given time. If they do start to regrow it’s a good idea to give them a feed with a general purpose fertiliser such as Growmore to encourage healthier and more vigorous regrowth. If no new growth is seen by the start of the summer then definitely dig it up and replace it.
The worst plants to be damaged seem to be Phormiums, Cordylines, Hebes and Pittosporums. Here’s a few tips of what to do with them.
Phormiums – The larger purple Phormiums seem to be worst affected and the larger green ones less so. First of all, you have to make a judgement call as to whether you think it has completely died and needs to be dug up or whether it is worth saving. We have certainly seen plenty of dead ones; if all the leaves are brown and desiccated and there’s no sign of any live growth at the base, get rid of it. If there is any live growth cut out all the bent, dead and damaged leaves. On some badly hit plants this may mean you have to cut back most of the leaves. This may look a bit odd but with any luck, once it warms up, it will reshoot and by the end of the year hopefully, it will look more like a Phormium again. Remember to give it a feed with something like Growmore in April / May. This is very much a wait and see approach and depends on how neat you like your garden to look. If you are happy to be patient, the plant may come back. Fingers crossed.
Cordylines – These seem to have been universally mullered (technical term) in most people’s gardens and again it’s the purple ones that have been the most badly affected. The foliage has gone brown and dry and totally collapsed. The thing to do here is to be patient, investigate the growing points when it gets warmer in April and probably best to leave the dead leaves to cover and insulate the growing points until this current cold spell is over. When it does warm up strip the dead leaves off to tidy up the plant. If it’s a small plant and both the growing point and the trunk is mushy, I’d get rid of it. If it’s a bigger plant and the trunk seems firmer I’d cut it with the loppers or pruning saw a bit further down and hopefully it will reshoot. It may look drastic, but I’ve done it on many occasions and its always worked and you end up with a strong plant again.
Hebes – The larger, fleshy leaved hebes seem to have been hit the worst. In most cases they seem to have been killed completed. If they are youngish plants, recently planted in the last couple of years, it’s probably curtains. On one planting scheme that I’ve seen, planted by a developer last year, nearly 100 varigated hebes had to be thrown away. If yours look brown and crispy and if the bark at the base is cracked, dig it up and replace it with something else. More established plants may be OK but the best advice is to leave it alone for a couple of months. It may reshoot further down and if it does just prune off the dead bits.
Pittosporums– Pittosporums, especially P.tenuifolium, are only frost hardy down to about -8 degrees C, so many have been damaged on exposed sites this year. We have seen lots of young, recently planted Pittosporums (such as Pittosporum tenuifolium) are completed defoliated and are stone dead. If yours are like this dig up and get rid. More established ones may just need the dead bits tidied up. If not completely dead be patient and wait and see.
Hardy Fuchsias – These die back according to the severity of the winter. Some years they just die back to a main stem and then the new growth will come from there. This year most hardy fuschias have been knocked right back down to the grown. Again wait and see, they may come back from underground. If they look as though they are going to just cut the dead bits back.
Choisya ‘Sundance’ – these can be quite tender at the best of times and frost damage was inevitable on new growth. Don’t be tempted to cut these dead bits off just yet. Like many things wait a bit longer when it warms up so that any new cuts won’t do any further damage.
Trachelospernum climbers – lots of these have got brown – purple leaves at the moment but the extent to which it may or may not have died back is difficult to tell. You’ll have to wait until May or June to find out at which point tidy up the dead bits then.
Bay topiay –lots of standard bays are looking sad. If the bark on the stems are cracked and peeled away all the way around, that’s the end of the plant. If you just have brown leaves and there seems to be some live stems you should hopefully be OK and the plant will come back given time.
Here’s a few other gardening jobs to get stuck into if it does warm up.
- Prune your roses. Now’s the time to prune your rose bushes if you haven’t already done so. Don’t get too stressed about the technical side. What you should do is prune back to an outward facing bud, taking the bush down to about half to a third of its height. You should also prune away any dead or diseased stems and burn them and prune away any stems that cross each other. You are aiming for a good open bush. This isn’t something to worry about too much – I know of at least one rose grower who does his rose pruning with a hedge trimmer and it doesn’t affect the flowering one bit.
- Prune buddleias and dogwoods. Ideal time for cutting back Buddleia davidii to encourage flowering. Some plants that have got out of hand may need to have quite a bit taken off. Cut back the colourful stemmed dogwoods such as the red Cornus Alba. If you cut the stems back almost to the ground (15cm) it will ensure a new lot of colourful stems for next winter.
- Trim your grasses. We always give our ornamental grasses a haircut this time of year, ready for the new verdant growth to push through. Don’t cut too low only down to about 15cm. Good time for trimming back pampas grasses; we take a hedge trimmer to it or if you are in an appropriate location set light to it to take it to take off the dead bits and encourage new growth.
- Lift and shift your perennials. Good time for dividing and moving herbaceous perennials such as Phlox, Asters, Rudbeckia and Alchemila
- If you want to transplant Snowdrops, a good time to do this is after they have flowered when they are still ‘in the green’.
- Get out and dig over your bare soil now that the conditions are right if you haven’t already done so. For most vegetables you want to aim for a consistancy of coarse breadcrumbs before you sow.
- Start to sow some veg seed outside such as lettuce, raddish and cabbage towards the end of the month.
- Start to sow Cosmos seeds inside.
- Onion sets can be planted out now.
- Chitting Potatoes – To get your potatoes growing away better, you should chit them to encourage sprouting. To do this place in a tray or egg box and keep somewhere bright and cool for a couple of weeks. Put them ‘rose-end’ up (The end with the dormant eyes upwards). Earlies you can think about planting out at the end of the month
- Get the mower out and make sure it works. You may also want to think about a spring lawn treatment for next month.
- Plant lily bulbs ready for the summer.