Thompson & Morgan
Facebook Q&A Session 27th July 2012

 

Thompson & Morgan Facebook Q&A Session 27th July 2012 - Your horticultural questions answered.


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Name: Nicola Guntrip

Question: Hi all quick question for you my Pyracantha has already got berry's on it in July is this normal as it said on label that they have berry's in Oct-Dec time. Thankyou

Answer: Hello Nicola. It’s been a very strange year for many plants, with a hot spring followed by cold, wet weather for most of the summer so far. Under such circumstances it is quite normal for plants to become a little out of synch with the seasons, producing flowers and fruits at unexpected times. Don’t worry about this - it may reduce your autumn display this year but things should get back to normal next spring.


Name: Louise Johnsen

Question: I’ve recently bought everlasting Sweetpeas from you but they have developed a mould like substance on the leaves any ideas on a cure.

Answer: Hi Louise. A picture is always quite handy for diagnosing problems, but without one my guess would be that your Sweet Peas are suffering from powdery mildew. This is a very common fungal disease, particularly at this time of the year. The spores of powdery mildew are airborne so they spread very easily. Luckily it’s fairly easy to control with a suitable fungicide. I would suggest using Westland Plant Rescue Control ready-to-use-spray, Scotts Fungus Clear Ultra, or a similar product. Look for the active ingredients of Myclobutanil, Difenoconazole, or triticonazole. I hope this helps.


Name: Tracie Watson

Question:Any idea why my stock and corn flower already starting to flower as shouldn't till next year so does this mean they won't next year, I planted them out on time it said on packet. Also perennials that I got recently from yourselves and ones I've started myself - do I wait till next year to plant them in garden thanks. And can I ask if a plant has to be a certain size before I plant them out as I think I'm planting out too quickly.

Answer: Hi Tracie. Stocks can be sown as annuals in late winter/ early spring for flowering in the same year. Alternatively you can sow them in mid-summer for flowering in the following spring. I suspect that you sowed them around February/ March time so this would be perfectly normal for them to flower now. If you have any seed left then it would be worth sowing some now for overwintering in a cold frame - they should then flower next spring. Likewise the Cornflowers are sown in spring for flowering in summer but if you wait until August/ September before sowing then they will flower in early summer the following year.

Regarding your perennials, I would always suggest that it’s worth growing them on in containers until they are large enough to cope with planting into borders. The main problem for young perennials being planted into mature borders is that they will be out-competed for light and space by larger, more established plants already growing there.

I personally prefer to keep potting perennials on into progressively larger containers as they grow, until they are in at least a 1 litre sized pot. (Check the bottom of the pot - it should say the size there). If I am planting into really established borders I might even wait until they are in a 2 litre pot - this might take three growing seasons from seed. Also, I would be inclined to plant them in late autumn once the other plants have died back. This will give them a chance to get their roots established over winter, while the rest of the border is relatively dormant. Once spring comes they will be in a better position to compete with more mature plants. However, if competition is unlikely to be an issue because it is a completely new border then you can plant them out much sooner, from pots as small as 9cm diameter. They should establish quickly without any competition. I hope this helps, Tracie.


Name: Tracie Watson

Question: Well my first year gardening so very new. Would appreciate any tips about what to plant bearing in mind I live in Sunderland, south facing and clay soil.

Answer: Hi Tracie. People often feel slightly disadvantaged by having a clay soil but actually clay is extremely fertile and you can grow a really good range of plants on clay. If you are dealing with heavy clay then it would definitely be worth adding some well rotted manure to help break it up and improve drainage. Here are some planting suggestions.

These are just a few ideas, but there are lots of plants to try. Take a look at what is growing well in your neighbours’ gardens as these plants will probably enjoy your garden too.


Name: Adam Jacobs

Question: Any chance of Sue having a look at this one? My melons seem to have succumbed to some horrible disease. This photo was taken a few days ago, but the plants have now been completely destroyed by whatever it is. Any ideas what's happened and how to prevent it happening next time? I still have watermelons in my greenhouse that need planting out soon, and I don't want them to go the same way.

Answer: Hi Adam. I don’t think that this damage has been caused by a disease. It looks as though the plant has suffered from wind chill which has caused it to die back. This is quite common in melons but particularly so during a cold, wet summer. I would be inclined to plant them under cloches initially until they are well rooted in and growing strongly. You can even grow them in a cold frame. It will give them a more protected environment while they establish.

Root rot can also cause melons to die back if the soil is too wet. It would be worth inspecting the roots when you pull the damaged plants up. If root rotlooks as though it may be a problem then try planting each melon on a slightly raised mound to help drain away excess water. Melons can be tricky to grow in the UK but don’t be put off - the weather this year has been particularly bad and ruined many people’s crops. It’s definitely worth another go next year.


Name: Susan Oldfield

Question:My sweet pea leaves have ALL developed leaf curl in the past fortnight. I'm trying to grow flowers for a wedding on 18.8. Will the flowers be affected? What can I do to cure the problem? The seeds -bought from a specialist grower - not your firm - were advertised as virus-free. What has gone wrong?

Answer: Hi Susan. What a shame. Leaf curling and stunted or twisted growth is a good indicator of a virus and unfortunately Sweet Peas are quite prone to this. Viruses are most commonly spread via aphids so it is well worth checking your plants to see if you can detect any signs of insect infestation.

Unfortunately there is little that can be done to save virused plants. They will probably still flower, but the vase life is likely to be reduced and the flowers themselves may also show signs of colour-breaking and distortion. The other possibility is Leafy Gall which can cause similar symptoms, but is a soil inhabiting bacteria. As with viruses, there is no real control for this pathogen. It is important that you disinfect your hands and tools after handling these plants to reduce the risk of it spreading. Sadly, infected plant material is best removed and burnt.


Name: Gaz RocknRolla

Question: Tree problems. Could it may be fungus issue, if so or not how do I treat the problems? Though unsure what's wrong with my other apricot tree either? My other one is doing fine.

Answer: Hi Gaz. It looks like your Walnut, Apple and Hazelnut all have a touch of black spot developing. As they are not fruiting anyway then you could spray them with a fungicide, but to be honest this is unlikely to be a severe problem for your trees and it is best ignored. The wet summer this year has provided perfect conditions for the spread of fungal diseases. Clear away and burn any fallen foliage throughout the season and also in the autumn to prevent the spores overwintering in your garden.

The apricot is more difficult to explain. It’s hard to tell from the photos but I am sure that I can see some signs of webbing on one or two pictures and this might indicate that the tree is suffering from spider mite. This is quite often found on peaches and apricots that are grown under cover, but can also affect outdoor plants. Take a really close look - you will probably need a magnifying glass to spot these tiny mites. Spider mite is a particularly difficult pest to eradicate as it readily develops tolerance to chemical controls and generally requires several applications of chemicals in order to eradicate all stages of the lifecycle (mites, nymphs and eggs).

Biological controls such as the predatory mite Phytoseiulus persimilis are the most effective control against spider mite. However, it requires a minimum temperature of over 16ºC (although daytime temperatures of 21 ºC are preferable) and there needs to be sufficient numbers of spider mite present for the predatory mites to feed on. Obviously, if you choose to use biological control then you cannot also use chemical control as this will kill the predatory mites! Of course it may not be spider mite at all, but unfortunately I can’t really tell from the pictures.