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Bedding plants & patio plants
Help solve your gardening problem. Here are the answers to some commonly asked gardening questions about bedding plants and patio plants with hints, tips and advice.
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I always have problems with plug plants. Can you give me any advice? I grow them on in a plastic plant house.
Plug plants can be tricky to get to grips with – they are ‘baby’ plants and like human babies are very prone to damage if not given a little TLC to get them going. Hopefully, the following will help.
As soon as the plants arrive, unpack them, place in a light place, but somewhere they won’t get hot, direct, burning sunlight. Water if the compost has dried out – don’t if it is wet. Give them a day or two to recover before potting up.
When potting up, use a good, multipurpose or peat-based compost. Don’t tease out the roots as this can set them back. Don’t overpot them – that is don’t use too big a pot; most plugs should go in 7.5-9cm (3-3.5in) pots. Give the plants/compost a good watering to settle them in to their new homes.
After potting on, put them in the plant house, with the zip done up to prevent wind damage and fluctuating temperatures. But again, keep the plants out of direct sunlight to prevent burning. Either move the house somewhere suitable or cover it/the plants with fleece to shade them.
Watering should only be done when the compost starts to dry out – that is the top of the compost turns light brown. Alternatively, pick up the pot to guesstimate its weight; get used to the difference in weight between moist compost and dry compost. Overwatering at this stage can/will rot the roots.
As the plants grow and fill the pots they will dry out more quickly, so water more regularly.
Watering from the bottom, using a tray, is a good way of doing it – but the problem may lay in the fact that the pots are sitting in the water for too long. Basically, once the compost has been thoroughly re-wetted, the plants should be removed from the water. If you can’t stay around to do this, gauge how much water the plants use, so you only put in that much, so the plants take up all the water and don’t sit in it for extended times.
All composts react differently – those based on coir, for instance, can look dry on the surface but may be soaking wet lower down. I haven’t got to grips with coir composts, which is why I always use peat-based ones for young plants.
I have planted some geraniums (pelargoniums) in pots. They all have a flower bud, but someone told me to cut out the first bud to get more blooms for the rest of the year. Is this right?
That depends! If the plants are small – say plug plant size - then yes I would remove the first flower bud(s) to allow the plants to put their energy into root growth and getting established. That way you’ll get a much better display throughout summer.
If they’re reasonably sized plants – say bought in a 10cm (4in) pot or bigger then you can probably get away without – but again you may get better results if you do!
Make sure you look after the plants throughout summer. Five weeks after they’ve been in their pots, you can start giving a 10-14 day liquid feed using a high-potash fertiliser. Or, better still, use a controlled-release fertiliser in the compost, which will feed them all summer long from one application. Remember to carefully snap off the flower stalk as soon as the flowers fade to help ensure further flushes of flowers.
How do I overwinter a standard fuchsia?
Standards of even otherwise 'hardy' varieties of fuchsias must be kept frost free during the winter - the stem is very prone to cold damage. So, the best place for them is a frost-free (minimum temperature 5C/40F) greenhouse or conservatory; a shed, garage or even cool spare room will provide good alternative winter quarters. Wrapping pipe lagging or sacking around the stem and draping a layer or two of fleece over the head will provide extra protection when temperatures drop really low.
Before moving the plant indoors it is a good idea to cut back the head to a framework of main branches, removing all weak growth. When overwintering keep the compost just moist and don't feed.
At the above temperature the plant will lose all its leaves and can be started back into growth in spring. At higher temperatures (10C/50F) you can keep the plant growing through the winter, which may give better results in the spring - bare branches don't always shoot well and sometimes produce an uneven head of branches and foliage. In this case you will have to give the plant more water during the winter.
The leaves of my datura (angel's trumpet) have small holes in them. What is causing them and how can I treat it?
Without seeing a sample of the leaves it is difficult to make an exact diagnosis, but the usual culprits are caterpillars or capsid bugs - although slugs or snails could be to blame.
Caterpillars tend to make irregular shaped, 'gnawed' holes. The caterpillars are often very small and difficult to spot until the damage is done. Spraying with a caterpillar-specific insecticide will kill any remaining pests, but I would imagine that they have now moved away from the plant.
Capsid bugs are sap suckers that make small holes in the young leaves which then expand as the leaf grows making quite sizeable holes. Spraying with a systemic insecticide, such as Provado Ultimate Bug Killer, would help kill any capsids as they suck the sap.
Make sure you clear up these pest before you re-house your plants for the winter.
I take lots of pelargonium cuttings in the autumn but have few successes. Why?
The main secret of success is to take the cuttings early enough. Most cuttings taken in the autumn don't root quickly enough to make a good-sized plant before winter. If the compost is kept too wet and the cuttings don't have a strong enough root system they tend to rot off. The best time to take cuttings of pelargoniums, and other half-hardy bedding and patio perennials, is late August.
The best cuttings come from young shoots that are not flowering. If your plants don't look suitable cut back some of the stems to produce strong, new shoots.
Insert the 7.5-10cm (3-4in) long cuttings in a sharp, gritty compost and don't cover with a propagator or polythene bag. Place the pots somewhere warm - a thermostatically-controlled propagator will give the best results - and out of strong sunlight until the cuttings root. Aim to keep the compost just moist.
I've had a wonderful show of geraniums (pelargoniums) this year. Can you tell me how to keep them for next year?
Geraniums (pelargoniums) are not hardy and will need overwintering in a frost-free place. A greenhouse or conservatory is best, but anywhere that can be kept at 4-5C and with some light will be OK.
Carefully lift the plants from the pot. Remove all dead, diseased or damaged leaves, spent flower spikes etc. If the plants are very large prune back some of the shoots by up to one-third.
Then pot up the plants individually in pots that will just hold the rootball (remove excess compost and any loose roots first). Fill in around the sides with fresh compost. Keep the compost just moist - certainly don't overwater them.
There is a correlation between the amount of light:water:temperature. You can keep plants overwinter at temperatures lower than 4-5C (but don't go lower than 2C) by keeping the compost slightly drier. In such conditions they won't grow much, but it's important they aren't kept in a lot of light (which will stimulate them into growth and so they'll need more water and higher temperatures). I hope this makes sense!
I've had a gorgeous display of 'Jamaican Mist' antirrhinums this summer. Can I extend the display and keep them flowering for longer?
It is possible to obtain a second flush of flowers by completely removing the flower spike as soon as the flowers fade. This way the plant won't put all its energy into producing seeds.
Then water with a liquid feed that is high in potash - such as a rose or tomato fertiliser - to help encourage more flowers. Always keep the soil moist.
I want to grow Surfinia petunias from seed, but have been told that I can't. Is this true?
True. Surfinia petunias are grown from cuttings, taken in spring or the end of August for overwintering in a frost-free greenhouse or similar.
Although the plants are male sterile - they don't produce any viable pollen - they will set seed if they are grown around other petunia varieties. You can save the seed and sow it in spring but the resulting plants won't be true Surfinias. They will be trailing, although they tend to be more sprawling and open in habit than Surfinias, and the flower colour won't be the same as those the seed was taken from. Even so, it is a cheap and easy way of producing more plants.
If you want to buy seed of a quality trailing petunia, then look out for the Wave series - they produce good plants with masses of flowers.
My display of African marigolds has been ruined as the flowers keep turning mushy. What am I doing wrong?
The large flowers of African marigolds often turn mushy when they fill up with water, which causes the flowers to rot. You should remove affected flowers as soon as you see them or the rot can work its way down into the rest of the plant.
When watering try to make sure you keep excess water away from open flowers - watering around the soil only.
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