Thompson & Morgan Facebook Q&A Session 10th February - Your horticultural questions answered.

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Name: Alejandro Canepuccia

Question: I just purchase some Lathyrus seeds. After seed germination, could you be so kind to recommend me the best conditions (soil mixture, PH soil, water condition and light) for have higher seedlings viability and have a good growth of the Sweet Pea in my garden. I purchased Lathyrus latifolius mixed, L. odoratus Floral Tribute and L. odoratus Winston Churchill.

Answer: Hello Alejandro. Sweet peas are fairly straight forward to grow but here are some tips to help you. Sweet Peas have deep roots and will benefit from being grown in a deeper container than many other species so you might want to start them off in root trainers. Alternatively you can just use ordinary 7.5cm (3”) pots. You can sow 3 seeds per 7.5cm (3”) pot at a depth of 1cm (½”) using a free-draining compost such as John Innes No.2. Place the pots in a propagator, or seal them inside a plastic bag at a temperature of 20-25C (68-77F). Germination usually takes 10-21 days.

Once germinated, grow your sweet peas on in bright, cooler conditions – unplug your propagator and take the lid off. Once they are growing strongly, and are fully rooted into their pots, acclimatise them to outdoor temperatures before transferring them to a cold frame outdoors. Pinch out the growing points of each stem once the second pair of leaves has opened to encourage bushier growth.

Later you can plant your sweet peas outdoors at a distance of 23cm (9”) apart in any well drained garden soil in full sun. Train the stems onto a suitable support such as trellis or a free standing climbing frame. Try using our sweet pea support rings to tie the stems to their growing supports while they become established. For more information, take a look at our article on ‘How to grow sweet peas’.

Name: Nial Hill

Question: Do you sell a red coloured flower with not much green leaf that would make good ground cover. Basically I want to do a shape in the grass and plant flowers so they fill it red, any advice greatly appreciated.

Answer: Hi Nial. You could try some red Nasturtiums such as ‘Mahogany Jewel’ or ‘Cobra’ which would make superb annual ground cover. Petunias make good, long flowering ground cover too – how about Petunia ‘Mirage Red’? Or could opt for a bright red bedding pelargonium such as Geranium ‘Best Red’ which will certainly give you a bright display this summer.

If you would prefer a longer lasting planting scheme that will return each year then Lily ‘Red Carpet’ makes a fantastic display for summer beds when planted closely together. If you are planting in a really dry, sunny spot then perennial Delosperma ‘Red Mountain’ would be ideal, although it will take a few years to establish before it really looks spectacular.

It really depends on whether you are looking for annuals, bulbs or perennials, but I would suggest that you browse our annual bedding plants if you are looking for colour this summer. Hope that helps Nial.

Name: Kay Rogers

Question: Question for Sue: My Penstemons have been flowering until a couple of weeks ago. Should I cut them down? And if so, how far? Also, I have a small blackcurrant, should I prune that? Thanks

Answer: Hi Kay. It’s a good idea to leave the old foliage of your penstemon intact until spring to protect plants during winter. Wait until the weather warms up in April or May and you will be able to see where the new shoots are springing from. If they are emerging from the base of the plant then you can cut back the old flowers and foliage close to the bottom of the stems. If shoots are emerging from higher up then just reduce the old stems back to where new growth is seen.

Your Blackcurrant can be pruned during winter so February is a good time, (although I would wait until this very cold weather passes!) If you have planted your blackcurrant in the last 4 years then simply remove any weak or damaged wood from the base of the stem. Try to retain a basic structure of up to 10 sturdy stems to create a nicely shaped, open bush. Blackcurrants fruit on young wood, so after the fourth year you can start to encourage fresh new shoots to develop by removing a third of the oldest stems each year, cutting them back to the base of the stem. Hope that helps, Kay.

Name: Angie Lambert

Question: Can anyone tell me when it is best to prune my passionfruit, it's quite unwieldy and has a lot of dead wood under the green.

Answer: Hello Angie. It’s a bit chilly for pruning Passion flowers at the moment. Pruning is best undertaken in the spring. Start by pruning out any dead or damaged shoots. Then reduce the remaining stems to fit the growth to the available space. Try to form a framework which can be tied in to its supports with soft ties.

Later in the year, after flowering, you can cut back any flowered shoots to two buds away from the framework of stems. Try not to prune any harder than this as hard pruning may forfeit any flowers next year. Best of luck Angela.

Name: Christina Goozee

Question:Probably a silly question, but I have a container peach tree in the conservatory which is in full bloom. Will it self fertilise or will it die off as no insects to pollinate at the moment? It is "Bonanza".

Answer: Hi Christine. I would imagine that your Peach tree is flowering slightly early because it is growing indoors and thinks that spring has come already! Don’t worry, this is not a problem. Even though there are not many pollinating insects about at the moment you can still pollinate by hand. Use a small artists paintbrush and move from flower to flower tickling the inside of each blossom with the tip of the brush. If you are using a garlic based biofume candle then your plants will be perfectly safe and you need not remove them from your conservatory. However, if it is a sulphur candle then you should remove your plants first and ventilate your conservatory thoroughly before returning them to it.

Name: Julie Atkinson

Question: For the 2nd early varieties I have, should I keep them in paper bags for a bit and start to chit them in a few weeks?? Also, can anyone tell me the ideal temperature for chitting? Thanks :)

Answer: Hello Julie, second early potatoes are traditionally planted from mid-March onwards. It normally takes about 6 weeks to get good ‘chits’ on your potatoes, so you could start chitting them now! If you do want to hold off chitting for the moment, keep your potatoes in their bag somewhere very cool, dark and frost-free. If kept too warm they start to sprout in the bag and produce spindly white shoots that get a little tangled.

With regards to temperature, you can produce decent chits at a temperature of around 10-15C, but don't get too worried about temperature. I would just keep your potatoes somewhere fairly cool but frost-free such as a North-facing windowsill in a porch or unused room. Avoid very warm rooms as the potatoes will sprout too quickly and early for planting, and the shoots will become tall and liable to snap. I hope this helps Julie, good luck with your potatoes this year!

Name: Dawna O'blivion

Question: Hi, I'd planted tulips in the fall, after the warm winter they poked up and got leafy, some much more than others, it's now cold and snowy, will the tulips be hurt by this? I'm in London, thanks for advance for any advice :)

Answer: Hi Dawna, new tulip growth is fairly frost hardy and would only suffer damage in extreme weather. My tulips are happily poking through the snow at the moment! If you’re concerned they’re becoming damaged then you could put some dry mulch around your tulip foliage, such as straw or leaves to give a few degrees of added protection. You could also lay horticultural fleece over them until the weather improves. If they are in containers then why not move them to a sheltered spot outdoors (next to a warm house wall) for added protection.

Name: Amanda Gorry

Question: Can Sue help me with this question? Sadly, my lovely wee dog (a mini Yorkshire Terrier) called Ferne had to be put to sleep recently. We are looking to bury her ashes in a container with a lovely plant on top (so we can take her with us if we ever move house). I wonder if Sue has any recommendations for a plant we could use - Is there a nice fern that would last all year or perhaps something nicely scented? I tried to find a plant named Ferne but could only find actual ferns. We live on the west coast of Scotland so it’s not that warm & can be very wet and our garden faces East (can be sunny). – thanks

Answer: Hi Amanda, I’m sorry to hear about Ferne. Your garden does sound ideal for ferns – they enjoy damp and cool conditions in shade or semi-shade. Some of the best ferns for containers include the Aleutian maidenhair fern (Adiantum aleuticum), Lady fern (Athyrium) and Buckler fern (Dryopteris). These are deciduous so although they lack winter interest, many have good autumn colour, looking lovely as they unfurl again in the spring. For an evergreen fern you could try the Japanese holly fern (Cyrtomium falcatum), Soft Shield fern (Polystichum setiferum) or Hart’s tongue fern (Asplenium scolopendrium).

For scented plants, dwarf Skimmias are ideal for containers. These evergreen shrubs thrive in either sun or shade and have lovely scented flowers in the spring. Daphne x transatlantic ‘Eternal Fragrance’ is another small, semi-evergreen shrub with a delicious fragrance. If you’re happy to put an obelisk in your container you could try Clematis ‘Fragrant Oberon’, which is evergreen and sweetly scented in the spring with pale green flowers. There are many scented varieties of patio roses which are suitable for growing in containers although they need full sun to perform well. You can also try a Rose standard (which looks like a small rose tree) for that extra special container plant.

Moving away from shrubs there are a few scented perennials such as Dianthus (Pinks/Carnations), Agastache and Berlandiera lyrata ‘Chocolate Daisy’ which will do well in containers. All long-term container plants are best potted into a good quality loam-based compost such as John Innes No.2 for herbaceous plants and No.3 for shrubs and climbers. I hope this helps you find something special Amanda.

Name: Corinne Surkitt

Question: Hi there , I have a question for sue this week , to cut down on my watering for my containers I have used the moisture retaining gel crystals , i mixed them in with the compost but as soon as they have been watered they swelled up ( which of course they are meant to ) but it has meant compost has erupted over the edges of the containers . How do I work out putting enough compost in to plant things at the right depth then cover the roots and firm them in but not have it swell and flood out as soon as its wet ? Surely I can’t be the only numpty out there who has this problem ... well perhaps it is just me…

Answer: Hi Corinne, I’m sure you’re not alone with this! It’s worth checking you’re adding the right amount of granules - only very tiny amounts are needed per basket or container (often one level teaspoon but do refer to the manufacturer’s instructions). It may not feel like you’re adding much but these granules will hold up to 400 times their weight in water so a little will go a long way. I hope this helps!

Name: Kevin Joseph

Question: I started some begonia seed in early Jan and managed to germinate them, however they are growing very slowly. It’s taken a month for the true leaves to appear. I know the commercial growers have special lighting etc but is there any weak feed I can give them to speed up their growth. Thanks

Answer: Hi Kevin. Your begonias are behaving perfectly normally. Begonias are generally very slow to get going. You could give them a very weak solution of high nitrogen feed – they probably don’t have much of a root system at this stage so take care not to overfeed them. I would suggest a half strength solution once a week would be sufficient.

Begonia seedlings are susceptible to cold draughts – I always keep mine in a square wooden frame on the bench of a heated greenhouse with a sheet of clear plastic pulled over them. The plastic can be partially rolled back during the day to provide adequate ventilation, and pulled across at night to keep them snug. It just gives them a little more warmth, which speeds up their development slightly. Don’t worry Kevin, they will speed up their growth once the weather warms up and the daylight lengthens.