Thompson & Morgan
Facebook Q&A Session 1st June 2012


Thompson & Morgan Facebook Q&A Session 1st June 2012 - Your horticultural questions answered.

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Name: Kay Rogers

Question: Question for Sue's session please. My peach has suddenly developed peach leaf curl and all its leaves are curled up. Is there anything I can do now to sort it out - can't really pick off the leaves as it has affected all of them.

Answer: Oh dear Kay. I’m afraid that once the symptoms of peach leaf curl are spotted in spring it becomes very difficult to treat the problem. This is why most treatments for peach leaf curl are preventative rather than curative. The fungal spores of peach leaf curl require moisture to germinate, so this infection occurs particularly during wet spring weather.

You will need to spray the tree in autumn and again in February with a copper based fungicide. I would suggest that you might need to follow up your February spray with a second application about 2 weeks later. If your peach is wall trained then you can erect an open ended screen to cover the tree from late winter to May to keep the rain off, thereby preventing the spores from germinating. I know this sounds a bit extreme but this technique has been proven to be very successful.

For this year, I’m afraid that all you can do is collect up the infected leaves and burn them or remove them from your garden entirely - do not add them to the compost heap. Better luck next year Kay.

Name: John Thompson

Question: Question for Sue: In the world of companion planting, when it says don't plant something 'near' something else, how far away does it need to be? 1 foot? 2 foot? 5 foot? I've looked and looked for an answer plus asked other gardeners but no-one seems to have a definitive answer. Cheers.

Answer: Hello John. There is no definitive answer to this question as it really depends on how much space you have available and what crops you are growing. Rather than putting a precise measurement on how far apart these crops should be, I would suggest that you simply try to avoid planting them directly next to each other. If you have a large plot then you can plant them in different areas provided that both crops will still receive adequate growing conditions. Companion planting isn’t an exact science so you can afford to be experimental and see what works on your plot - this does however, require a little bit of extra planning before you plant! Best of luck with it John.

Name: Pauline Irvine

Question: Hiya I've just noticed a bunch of white flies on my orange lillies. Have you any ideas on how to get rid of them safely without damaging the lily? I gave it a slight shake but they didn't move, and they're on the top of the leaves rather than underneath. They're about the size of green fly.

Answer: Hi Pauline. The problem with whitefly is that they have a very fast lifecycle so they can be difficult to control. This is why spraying with soapy water is rarely effective on whitefly - you would really need to spray them every day!

There are a number of insecticides that can be used to control whitefly. You can try a contact insecticide such as Bayer Sprayday Greenfly Killer, or better still a systemic insecticide such as Westland Plant Rescue Bug Killer for Ornamental Plants (do not use this on fruit or vegetable crops). Systemic insecticides are absorbed into the plant tissues so they protect the plant from the inside out.

If you are growing your lilies in the greenhouse then you may prefer to use biological controls such as the tiny parasitic wasp Encarsia Formosa. Biological controls are often far more successful in the greenhouse than insecticides.

Of course, if you only have a few plants that are affected then you could just squash any that you see and wipe the plant with an insecticidal soap (remember to wipe both sides of each leaf as the nymphs live on the undersides of the leaves. Hope that helps Pauline.

Name: Keith Drinkhall

Question: Could you please tell me what this is it was grown from a packet of cottage garden seed last year. It has pods on it with seeds in them.

Answer: It looks like Lunaria annua (syn. Lunaria biennis), commonly known as Honesty. I can’t see any seedpods in your photo but they will be flat disc-like and translucent. These seedpods are very attractive and make superb additions to dried flower arrangements.

Name: Kaz Prescott

Question: Can anyone give me any info on this plant... I bought it today but all it says is "fuchsia on a cane"... how high can it grow, is it a perennial.....? This is my first year growing fuchsias...

Answer: Hello Kaz. From the lengths between each node I would guess that this is an upright shrubby type, but not being a Fuchsia specialist I’m afraid I can’t give you a name. Fuchsias can range in size from 30cm to 2m or more, but many of the shrubbier varieties reach around 60-90cm. Some species are hardy while others are only half-hardy. The half hardy varieties tend to be grown as annuals in this country, but if you can provide them with frost free conditions over winter then they will happily continue growing year after year. Don’t forget that deadheading faded fuchsia flowers throughout the growing season will encourage more blooms to be produced.

Given that we don’t know whether this plant is hardy or not, I would personally err on the side of caution and plant it in a container using a good quality compost such as John Innes No.3. This way, you can stand it outdoors this summer and then move it inside in autumn to protect it from winter weather. Don’t be surprised if it looks pretty awful over winter. They always look very messy once they have shed their leaves. Wait until you see new growth in spring before you tidy it up with a little light pruning. I hope that helps Kaz.

Name: Cheryl Louise Gauden

Question: Hi I am wondering if you could help me I’ve stumbled across a plant/weed and not sure what it is. If it is possible could you tell me what it is please?

Answer: Hi Cheryl. The plant in your picture is Euphorbia lathyris, commonly known as the Mole Plant because it is thought to deter moles. Mystery solved!

Name: Michelle Williams

Question: Hi. I bought carpet lilies from you last year (via QVC) and they looked wonderful. They are coming up well again this year but one is looking very poorly. Its leaves are turning yellow and soft and the plant looks like it is dying. As you can see from the photo, I removed all of the dead leaves last week but the next ones up are dying now too. What is wrong with it? I think another may be going this way now as well.

Answer: Hi Michelle. It looks as though your lilies are suffering with fungal leaf blight or lily disease. This type of botrytis spreads freely in wet, humid conditions. The best way of preventing it is to grow lilies in sunny, well ventilated positions where the foliage will dry out quickly following rainfall. Also, take care to water directly into the soil and not from overhead. Let the soil dry out slightly between watering too.

You will need to cut off and burn any severely infected leaves and let them die back in late summer as normal. Destroy any remaining plant debris in autumn but the leave the bulbs where they are. Hopefully spring will be a bit drier next year and you will avoid the infection recurring. However, if this becomes an ongoing problem then I would suggest removing the bulbs and planting something completely different in this location as the spores can remain in the soil for at least 3 years.

Name: Shaun Osborne

Question: I want to treat my carrots to prevent carrot fly. What would you suggest to use?

Answer: Hi Shaun. The best way to protect your crop is to cover it with fleece or erect a barrier of clear polythene around the crop. Make sure that it is at least 18 inches high and partly embedded into the soil to prevent adult female carrot flies finding your crop. However, given that overwintering larvae emerge from the soil as adult flies in May and June, you should really have this barrier in place at bit earlier in the spring for it to be effective.

If you are experiencing problems with carrot fly you can time your crops to try to avoid periods when larvae are active in the soil. You can avoid the first attack by delaying sowing until late May when the first generation of larvae have already emerged as adult flies. Sow seed thinly to avoid the need for too much thinning as your seedlings grow. Also, when thinning seedlings, take care not to bruise the leaves as these produce a scent that will attract female carrot fly. You will need to remove the thinnings from the plot immediately and water your crop thoroughly to disperse the odour. You should also cultivate your soil thoroughly in winter to disturb the overwintering larvae and expose them to hungry birds. Hopefully you won’t have too much crop damage, Shaun. Best of luck.

Name: Christina Goozee

Question: Are the 16 spot ladybirds friend or foe pls.?

Answer: Hi Christina. The orange 16 spotted ladybird is a friend - it eats mildew and other fungi, as well as pollen, mites and aphids depending on what is available!