August is the latest month for taking semi-ripe cuttings. Fuchsias, Pelargoniums, evergreens, perennial climbers and most deciduous shrubs can still be propagated now, if you use the warmth of a glasshouse or tunnel to boost their growth.
Choose non-flowering shoots or cut the flowers off. Cut off slips 7-15 cm long by cutting just below a node (the thickening on a stem where a leaf or side shoot grows outwards). Clematis does better when cut between two nodes. Alternatively, tear off a side shoot of the right length with a piece of the main stem still attached like a foot, and cut off the ‘toe’ leaving the heel. Remove any leaves that would end up buried below the surface. Take plenty of cuttings: some won’t grow and the tighter they are crowded together the better they root.
Fill a container with a mix of two parts peat or leaf mould to one of sand, and water it well. Dip the bases of the cuttings in hormone rooting powder if you want, and lower them into holes dibbled around the edge with a pencil or similar. Firm the compost in well to ensure good contact with the cuttings.
The cuttings will lose water through their leaves and wither unless kept in the shade. Place them under solid staging, or rig up a shade above them. Use tinfoil or white plastic instead of black plastic, and keep it up from the plants to prevent heat build-up.
Lay clear plastic over the cuttings to keep in humidity. Hold it off the plants with hoops of wire or similar. Pelargoniums and plants with grey, silver, silky or hairy leaves resent humidity and are best left uncovered. Check the cuttings regularly and remove any dead bits. They are ready to pot on when they start growing.
Whether it’s Bali or Ballybunion, everyone wants to go away for a break. So what happens to your tunnel or your glasshouse while you’re gone?
Automatic watering is ideal. Be sure to set the controls well in advance so you’re sure it’s working well and regularly, and delivering enough water. Ventilation is easier; you can leave the vents wide open in mid-summer without fear of night frost but automatic vent openers are less liable to storm damage. They need no electricity and are easy to fit. Wedge doors nearly closed or screen them with wire mesh to keep out pets and wildlife.
Bribe a neighbour to keep an eye on it with free produce or a promise of looking after theirs later. Automatic watering and ventilators are good but nothing beats the human touch: unexpected problems can crop up (pun deliberate) and the comings and goings of neighbours deter thieves.
Move out pots to a sheltered, shady spot where they can get rain or be watered if needed. Remove more bottom leaves from your tomato plants than usual: the leaves on the top 70cm of the plants contribute most to their growth. This reduces their need for water and lets more fresh air around the plants, which helps control fungus diseases.
Remove flowers and developing fruit from plants to reduce the amount of unwanted and over-mature fruit growing while you’re away. It also further reduces the plants’ need for water.
Tidy up and clear out any weeds; also dead and dying leaves, dropped fruit and other plant remains that could host diseases. Bon voyage!
Written by horticulturalist Peter Whyte
Everyone with a polytunnel or glasshouse is tempted to grow tomatoes – and why not? They taste so much better when picked just before eating. Here are a few tips for the best crops.
Choose well-flavoured varieties like Shirley or Alicante. Some traditional varieties like Moneymaker are insipid. If you are buying plants, look for healthy ones about 20cm tall. Yellow leaves indicate poor feeding or cultivation and bluish or purplish leaves indicate chilling: such plants will take time to recover and crop later. Drawn, leggy plants will be the same.
If planting in the soil try to have the plants in slight hollows rather than on top of mounds, so water will soak in rather than run away. Water them in well, and let the ground surface dry off between waterings. Vine tomatoes need support: if using canes put them in before the plants to avoid root damage. Strings are better than canes for plants in grow-bags. Cherry tomatoes are wide and bushy plants, so give them plenty of room to spread.
Feed the plants with high-potash feed as per the instructions, starting when the first fruits appear. Tie in the growing vines to canes or wind the support strings around them regularly, as stems are hard to train when they thicken up. Hook very long trusses up on themselves or higher leaf-stems to keep them up from mud and slugs.
Break out sideways any side-shoots growing from the angles between leaf-stems and the main stem. Snap off upwards any dying bottom leaves to let light and air around the fruit. Bush tomatoes need no training. Pick a tomato by thumbing down on the knuckle just above it while twisting the fruit upwards. The green oil on tomato plants is irritant; wash your hands with soap and water afterwards.
Peter Whyte B Agr Sc (Hort), Nat Dip Sc (Apic), Dip Tr & Ed, MI Hort
|A customer visited us last week by plane! Birr Airfield is next door to us so we got a call to ask if we would meet him and bring him over which we did. He brought his mother (for her first flight) and no doubt they had a great view of our display of Greenhouses and Polytunnels from above. Of course nothing beats seeing them up close and getting a feel for size and quality, but it reminds me of the ad for the car where you find any excuse to go for a drive. Great stuff.|
Never mind how cold it is in your garden; the sun is getting higher every day and even short clear spells will allow it to build up a lot of heat in your glasshouse or polytunnel. You might think this is a good thing, but not always so. Lettuce seed won’t germinate if it’s too warm, and temperatures above about 35°C (95°F) will destroy the red pigment in ripening tomatoes so they never colour up properly. Overheated plants need more water to keep cool. As well as that, high temperatures put plants under stress and promote diseases such as grey mould and pests such as red spider mites. You can’t stand there 24/7, thermometer in hand, to open and close doors and vents with each change in temperature. Ordinary mortals adjust the ventilation once in the morning for the expected daytime temperatures and once in the evening for the night, and that’s near enough most of the time. The weather forecast can help you decide how much ventilation to give in the morning. A recording thermometer can show you how you did today, helping you to fine-tune your settings for tomorrow. End doors alone give enough ventilation for most polytunnels up to about 20 metres long. Side windows, roll-up vents and louvre vents are good but not cheap. Glasshouse vents can be fitted with gas-filled struts that automatically push them further open when they get warmer, without needing electricity. The best ventilation comes from a through flow of air, so open both ends of a polytunnel or more than one window in a glasshouse. Open many vents a little bit instead of opening two vents wide to reduce draughts. Be cool!
Peter Whyte (Lanscape and Garden Consultant) B Agr Sc (Hort), Nat Dip Sc (Apic), Dip Tr & Ed, MI Hort
Traditionally, people sowed vegetable seeds in their gardens on Saint Patrick’s Day. That was because they were off work and free to do it rather than weather and soil conditions being suitable. But, right enough, the soil is often dry enough to dig and warm enough for seed germination about then.
If you have a glasshouse or polytunnel you don’t have to wait for all that. You can sow crop seeds earlier under cover and have plants to put out instead of seeds, gaining several weeks of extra growth. Sow leafy crops like cabbages and lettuce in modules for planting out later, and also a few seeds in the border soil inside to mature early. If you have lots of room, keep one courgette plant growing inside until the outdoor-planted ones start fruiting. You can then chop it out and use the space for something else, but it will have been cropping for weeks by then.
Tap-rooted plants such as carrots can’t be transplanted and don’t take kindly to modules, but you can still sow some inside for early crops. Freshly-dug baby carrots, washed instead of peeled, and eaten raw are fit for a king.
Seedlings are easiest to raise in a heated propagator. If using it inside the house carry the seedlings out to a glasshouse or tunnel in the propagator with the cover closed to protect them from cold winds as the temperature shock would be too much for them.
The sun is getting stronger, so be prepared to open vents or doors on sunny days. But make sure to close them at night! Throw a sheet of bubble-wrap or fleece over plants on frosty nights.
We now have 15 Glasshouses and 4 Polytunnels on display at Polydome’s HQ at Crinkill House in Birr. With Birr Castle Demesne close by any green fingered people looking for a Greenhouse (Glasshouse or Polytunnel) will find the trip well worthwhile. As well as seeing the largest display of Greenhouses and being able to talk to product specialists to sort you out with the best Greenhouse or Greenhouses Accessories for your situation, with good places to eat locally and the renowned Gardens and Science Centre at Birr Castle it will be a great horticultural day out.
We have installed double sliding doors on our 5.5m wide Display Tunnel. They look great and overcome issues hinged doors can have on windy sites. A strong magnet keeps the two doors together when closed. More new products coming on stream shortly and as well as our 4 Polytunnels on display we now have 11 Glasshouses so far up as well.
Glad to say our Greenhouse Display area is progressing well. We have 9 Glasshouses and 4 Polytunnels up so far with more to come in the coming weeks and months. Our plan will be over time to develop the area to show not only the huge range of Greenhouses and Polytunnels we do but also giving examples of how they can be laid out, which is a question we are often asked by customers. We will also over time kit out many of the Greenhouses and Polytunnels with all sorts of accessories to demonstrate their use, so our display area will not just be for visitors wanting to buy a Glasshouse but a destination for proud owners of Greenhouses wishing to enhance and utilize their investment to its full potential. Our display area is open from 9am to 5.30pm Monday to Saturday (closed for a well deserved break between 1 and 2pm). Why not phone and make an appointment to ensure a specialist for the product you are interested in is available and minimize your waiting time.
Really enjoyed the Bloom Show. Apart from the great reaction to the Glasshouses and Polytunnels we had on display on our stand, the award winning Growhouse (Western Red Cedar Glasshouse) which we built in an award winning Garden generated a huge amount of enquiries. It was also wonderful to meet so many of our customers who stopped in to say hello. I find it is a very well run show with good facilities which helps to make attending and visiting a pleasurable experience. So put the date in your diary for next year everyone!