May is a dangerous month for greenhouse users. With all the talk about global warming and the evidence of it everywhere, you can easily forget that the risk of frost continues into May. The last likely frost might be in early May near the coast, but inland you are not in the clear until end of the month. Global warming is a long-term trend but there are still short-term highs and lows on the temperature graph.
Plants grow fast in May and quickly need more space. It’s tempting to move some plants out of tunnels or glasshouses to make room for the rest, but harden them off properly first and keep a sharp eye on the weather forecast. Be prepared to carry them back in on evenings when frost is predicted. And if you were tempted by the early displays of tender bedding plants in a garden centre, remember to bring them in too. Cold frames can protect plants from several degrees of frost, and plastic cloche tunnels give some protection from lighter frosts. Single small plants can be covered with upturned buckets or light materials such as straw or bracken fronds. Just make sure the wind doesn’t uncover them overnight and that you uncover them yourself next morning.
Poor Man’s Orchid or Butterfly Flower is a half-hardy annual which, when well grown, is covered in flowers that look a bit like orchids or butterflies. It is much easier to grow than true orchids. The flowers can be a single colour such as white, lavender, pink and red, or be bi-coloured, and/or have yellow throats. They last well when cut. Like all half-hardy annuals they can be grown from seed in a greenhouse and planted outdoors after the last frosts are over. But they can also be kept in a well-ventilated greenhouse to flower all summer. They do very well in pots and containers, where the root restriction seems to encourage them to flower better.
Sow the seed in trays or small pots; varieties differ in their need for light for germination so follow the seed-packet instructions as to whether to cover them with compost or not. Keep them at about 60°F / 15°C for 2-4 weeks; they are slow to germinate. Prick out the seedlings when big enough to handle, and pinch out the growing tips as they get taller to keep them bushy. Keep them in full light but shade them from hot sun. They prefer fairly cool conditions and become drawn and spindly if too warm. They don’t tolerate wet so give them perfect drainage, water them only when the compost is dry on top and never leave containers standing in saucers of water. Give them some tomato feed every two weeks. If you have a heated greenhouse you can sow Schizanthus in August or September for overwintering. Watch out for greenfly; the ferny foliage hides them well.
Thanks to Cambridge University for the photo.
Twin wall polycarbonate is particularly popular on the continent. One of the advantages is that it is virtually unbreakable, it provides insulation and diffuses the light to reduce sun scorch. One cannot see clearly through it though. It provides excellent insulation so if running a heater your fuel costs will be much lower than a Glass Greenhouse without insulation.
10mm twin wall polycarbonate is much stronger than the light 4mm and 6mm sold with cheap Greenhouses.
The size also is a new one to our display area being 2.36m x 4.58m.
Being a Janssen Greenhouse this model has the benefit of an extremely strong ‘box section’ aluminium frame which is powder coated in either Green or Black. This model with 2.01m high sides, a single sliding door, three roof vents and a louvre vent is €4,405 including delivery for the self assembly kit.
There are lots of optional add ons.
March is about as late as you can sow aubergine seeds and expect a reasonable crop. You could sow as early as late January if the weather is mild enough or if you have frost protection heating in your greenhouse. Cell-trays allow you to plant the young plants with less root disturbance, so they grow away faster than plants pricked off from traditional seed-trays. Sow two seeds per cell (if both come up snip out the weaker one). Place them in a heated propagator or on a warm windowsill; the ideal temperature is 20-25°C (68-77°F). Keep the compost moist but not wet. The seedlings can take up to three weeks to emerge.
Set out the plants in your greenhouse as soon as their roots fill the cells or the first flowers appear, if by then you can keep them above 10°C (50°F) or so at night. Night-time fleece covers help. Alternatively pot them on into slightly bigger pots that can be brought into the house at night. Space the plants about 45cm/18 inches apart for normal, and 30cm/18 inches apart for dwarf varieties. Pinch out the growing point s of the main stems when about 25cm/10 inches tall to encourage the plant to bush out. Keep conditions warm, bright and humid.
Pollinate early flowers with a small paintbrush; later flowers should need less help. Start liquid feeding with tomato food when the first fruits form, and mist the plants with water to discourage red spider mite. Leave no more than five fruits per plant and remove further flowers to divert their energy into filling the existing fruit. Remove dead bits from the plants to discourage grey mould fungus, and watch out for slugs, whitefly and greenfly. Good varieties to try are ‘Black Prince’, ‘Dusky’, ‘Bonica’ and ‘Giotto’.
Delighted to say our new phone system has been installed. We just need to get used to the new buttons and bells and whistles and tweek things a bit. Customers should also hear professionally recorded on hold messaging. Thank you for having borne with us.
Our new phone system is due to be installed on Tuesday which will be a terrific relief.
In the meantime please bear with us. We have only one incoming phone line working and have had to divert that to a mobile.
You can of course email us at email@example.com
We will be open for visitors as usual on weekdays and on Saturday from 9am to 5.30pm (closed for lunch between one and two).
You can get directions to us on the How to find us section of the home page of our website.
Many thanks, Jonathan Pyle
In case anyone is having any difficulty getting through to us, I apologise. Our Eircom phone system has gone kaput and they say that replacement parts are not available now that it is 7 years old (after charging 180 euro for one hour to advise me of that). I like the idea that whenever something goes wrong to use the opportunity to improve the situation even better than it was before the event – so we will be installing a new more efficient system as soon as the new providers who are based in Birr as it happens can do so. Have to pat the new people (Intellicom) on the back, I called and enquired about a new phone system, within one hour a sales man was in our office, two hours later he was back with a technician to do a survey and before the end of the day a quotation received and price agreed. Way to go lads.
In the meantime while we are sorting out this issue please contact us on (086) 805 8550 or email us at firstname.lastname@example.org
Janssens have launched their new 2017 brochure, it is nearly three times the size of the previous one at 64 pages. Just click on the image of the brochure to view it on drop box.
We can send anyone who would like to view it a link to do so online. Hard copies have not been received yet but will be available free of charge to all visitors to our display area. Glad to say we were involved in helping in a small way with this brochure by editing text and supplying images.
If last year you had problems with lime scale blocking up your greenhouse watering system, now is a good time to sort them. Hard water may eventually block up greenhouse sprinklers and seep hoses. Even if you have a water-softener for the house, it may not be economic to soften the water used in the garden. Buying new sprinklers and seep-hoses every other year is expensive and wasteful when they can easily be cleared.
Disconnect blocked seep-hoses and coil them neatly into the bottom of a large plastic bucket. The white plastic buckets with lids that garden products are often sold in are ideal. Put any plastic sprinkler components into the middle; it’s best not to add any metal parts as they might corrode. Following the manufacturer’s instructions, add de-scaler (lime scale remover) to just enough water to cover the hose in the bucket. Always wear hand and eye protection when doing this, and never handle powder products in windy conditions or you may get an eyeful. Snap on the lid tightly and put it out of reach of children and pets. Somewhere warmer is ideal as the chemical reaction between the de-scaler and the lime scale runs faster. When you need to re-install the watering system for the new season, pour the water away carefully where it won’t cause pollution and rinse all the parts with clean water.
It’s easier at this time of year to buy imported lettuce than grow it in your greenhouse or to grow rocket, endives and oriental greens instead, but lettuce is preferred in many households and home-grown is much fresher. Choose varieties that are tolerant of short days and low temperatures, and resistant to mildew. ‘Little Gem’ and ‘Winter Gem’ are cos-type varieties, ‘May Queen’ and ‘All the Year Round’ are butterhead types, and ‘Salad Bowl’ is a looseleaf type for cut-and-come-again harvesting. If in doubt check the information on the back of the seed packet.
You can sow the seeds thinly and 1cm deep in the greenhouse soil. Keep the drills about 30cm apart and thin the plants to the same spacing when they are big enough. This wide spacing leaves plenty of air between plants to discourage mould and slugs. Sow a little every two to three weeks for a succession of crops.
It’s easier to sow the earliest batches in cell trays with small cells. Sow just a few seeds in each. Keep them indoors to avoid slugs and mould, and don’t let them get warmer than 25°C (77°F) or they won’t germinate. Thin the plants to one per cell with a fine-pointed scissors as soon as they are big enough to work with, and plant them out as soon as their roots have bound the compost in each cell together. Keep the plants well watered, and ventilate the greenhouse whenever the weather allows. Water in the morning to allow the plants and soil surface dry out before night. Protect the plants from slugs and remove all weeds, dead leaves and rubbish. Harvest hearted lettuce by pulling whole plants, and looseleaf types with a scissors, leaving the plants to grow more leaves.