Thompson & Morgan
Facebook Q&A Session - October 15th

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Name: Joanne Lambert

Question: Was looking at planting 16 hanging baskets up for next september we are having our daughters wedding at home i love those massive petunia displays can you advise me which are the best for the job and how many i will need to order many thanks i have never made any before so any help would be fantastic.


Answer: What an exciting time for your family! First of all you will need to buy the baskets. Our baskets are 15” in diameter and as a rule you can normally plant 1 plant per inch of basket diameter for most bedding plants, including petunias. So 15 plants per basket should make a really full display.If you were planting larger, stronger growing plants such as fuchsias and geraniums then you would need to reduce this amount to about 5 to 7 plants per basket.


There are lots of petunias to choose from. Petunia purple velvet makes a bright display or for something more subtle try Petunia Frills and Spills. Most petunias are suitable for hanging baskets and provided that you pinch the growing tips out while the plants are still young, then you should have a really full and colourful display.

Have a browse through our petunia plants and seeds to see what will work best with your daughters chosen colour scheme. You might also like to read our hanging basket article for some tips on how to plant and grow hanging baskets.


Name: Mandy Price

Question: I cut back my asparagus a couple of weeks ago and now its throwing up new spears, they were 1 year crowns i planted in the spring, so i know i'm not supposed to harvest from them. Similar problem with my young strawberry runners I planted out a few weeks ago are now in flower, I've been pinching them off is that right?


Answer: Hi Mandy. Don’t worry about your asparagus too much. The weather is still warm enough for the plants to remain in active growth, so cutting back the old spears has just promoted a late growth spurt. Leave them to grow for now. Eventually these stems will turn yellow and die back naturally when the daylight hours and temperature decrease as winter approaches. Once they turn yellow you can cut them back again to about 10cm (2”) above ground level. Next year, you can probably leave it a bit later in the autumn before cutting them back.


It’s a similar story with your strawberry runners. There is no harm in them flowering now but as they won’t have time to produce fruit before the first frosts, then you might as well pinch the flowers off. Then the plant can focus its energy upon developing a good root system instead!


Name: Sarah Griffiths

Question: Any tips on what sort of seeds/plug plants I should buy for bedding plants next year? my garden is south facing and gets very very hot. I have my first greenhouse and want to start sowing seeds etc so any tips/ideas gratefully received. Thanks


Answer: Hi Sarah, there are a wealth of plants that will thrive in a hot, south-facing aspect – you’re very lucky! You’ll find that plants with silver or hairy foliage are well adapted to the heat such as Lavender, Eryngium (Sea Holly) , Californian poppies (Eschscholzia) and Marguerite daisies (Argyranthemum). You could also try night-scented stock for a beautiful fragrance.


There are lots of bedding plants that you could try. A lot of bedding plants originate from hot countries, such as Petunias, Zinnias, annual Verbenas, Gazanias and Gaillardias so they will be well suited to your gardens growing conditions. One of my favourites is a plant with succulent leaves called Mesembryanthemum (Livingstone daisy) and similarly Delosperma. They look stunning when planted en masse.


It’s great to hear that you have got a greenhouse. Greenhouses are ideal for growing tender vegetables such as tomatoes, cucumbers and peppers in the summer. In a south facing garden you will certainly need to think about ventilation and shading throughout summer to prevent heat and strong sunlight from damaging the plants. If your greenhouse is going to be unheated during winter then remember that frost will still affect the plants inside, so it’s best to get yourself a greenhouse heater and some insulation, or start off half-hardy annual bedding plants indoors!


Name: Daphne Cook

Question: How can I keep my begonia Apricot shades for next year, & will my laurentia come up again next year?


Answer:Hi Daphne, you can keep your Begonia ‘Apricot Shades’ for next year. Once the foliage has died back naturally (which should be starting now) you can either store them in their pots in a cool, dry place or lift and clean the tubers and store them in containers of dry sand or peat. Keep them at a temperature of 5-10C. It’s best to dust the tubers with a fungicide before storing them to prevent them rotting.If you decide to keep them in their pots, allow the compost to dry out and begin watering them again in the spring.


Unfortunately Laurentias are not hardy and most people find it easiest to buy new plants each year. But if you have the space you can dig them up, and plant them in pots so that you can over-winter them in a bright frost-free position. Alternatively you can take cuttings. Stem cuttings will root easily in compost with warmth and humidity (cover the pot in a polythene bag). After about 4 weeks they should have rooted. Move the new plants to a cool, frost-free and bright environment to over-winter. Good luck Daphne.


Name: Maria Tzirki

Question: Why did my onion sets bolt this year, I had very few onions from them but plenty of flowers


Answer: Onions tend to bolt in very unsettled weather. We had a very cold start to the year followed by very hot temperatures from late spring onwards. There’s nothing we can do to control the weather but making sure the soil does not dry out will help. Digging in organic matter prior to planting will help the soil to retain moisture.


It also helps if you purchase heat treated onion sets as these are less likely to bolt. Don’t be too hasty when planting out onion sets; normally they are planted between March and April.


Name: Tracey Dawson

Question: How do i get rid of bamboo completely? It’s a very invasive one we have tried cutting down to ground level and used the weed killer resolva, but it has started to come back again! HELP!! Thanks.


Answer: Oh dear Tracy. Bamboo can be very invasive once it becomes established, but don’t despair just yet! You mentioned that you have tried using Resolva. This herbicide mixes a contact herbicide ‘diquat’ mixed with the well known systemic herbicide ‘glyphosate’, to eradicate both perennial and annual weeds. It is the glyphosate that will be most effective on bamboo, and there are lots of products on the market that use this as their main active ingredient, including Roundup and Tumbleweed.


However, many persistent perennial weeds require more than one application of glyphosate to weaken and destroy the plant. Don’t give up after one treatment; you will need to keep on treating the new growth. If you keep treating the new shoots as they appear then you will eventually weaken the plant and have a better chance of controlling it.


Alternatively you could try digging it out or burning the new shoots off with a flame wand. Whichever method you choose, you will need to attack the plant several times before you have any real effect. You could even use a combination of these methods to make life really difficult for your bamboo - just remember that persistence is your key to success!


Name: Daniel Stewart Marshall

Question: Is it possible to grow Globe Artichokes in containers? If so how big do they have to be?


Answer: Globe artichokes can easily reach a height of 1.5m (5ft) and a spread of 90cm (3ft) so they are not normally considered to be well suited to containers. If you have room to plant them in the ground then you would almost certainly have better results. Remember that they make striking architectural perennials, so even if you have no space in your vegetable plot, they would not look out of place at the back of the flower border.


Having said that, I am a great fan of garden experiments, and it is always worth a go! You would certainly need to give them plenty of space and I would suggest that a container of at least 45cm (18in) in diameter would be required. Try to use a good quality compost such as John Innes No. 2 which is more suitable for a long term perennial planting than ordinary multipurpose compost. Good luck with this gardening adventure and please let me know how you get on.


Name: Gwenneth Cook

Question: I grew carnations from seed this year but they didn’t flower can anyone tell me why and should I take them in for the winter?


Answer: Hi Gwenneth, as Carnations are perennial, they will often start to flower in their second year. Although some have minimal flowers, it’s perfectly normal to only see foliage during the first year.


Most Carnations are hardy as long as the drainage is good so you shouldn’t need to worry about taking them in for the winter. However if they are in containers then it might be worth moving the pot against the shelter of a wall, just to keep the worst of the weather off. Next year they should be mature enough to flower brilliantly!