National Gardening Week 2016 – Gardening Questions Answered

pergola and path, Bodnant Garden, Conway Valley, Wales


National Gardening Week 2016 takes place April 11th – 17th.

There are many events happening around the country and free entry is on offer for quite a few gardens – all four of the Royal Horticultural Society ones and the Prince of Wales garden at Highgrove to name but a few.


Last year my  blog was inspired by gardening quotes; this year, my National Gardening Week 2016 blog takes the format of frequent gardening questions we’re asked at this time of year and helpful answers.


Do I need to clean all my plant pots before re-using them?

Hands up who hasn’t cleaned out plant pots ready for transplanting seedlings and taking cuttings? That’s most of us then!
The reason pots should be emptied of old potting compost and cleaned out is to reduce the risk of disease transferring to the new plants you put in them. Young plants from cuttings or seedlings are more susceptible than mature plants, but it’s good garden practice to clean the pots out anyway.

clay plant pots in potting shed, garden sundries

You could make it part of your spring cleaning tasks; and you may find the children enjoy helping as it’s a messy job involving water play and old toothbrushes.
Use a proprietary cleaner, or a homemade vinegar/ sodium bicarbonate solution; 1 litre water, 2 tbsp bicarb of soda or a dilution of white vinegar 1:8 in water. Old toothbrushes make good tools to get clean right to the bottom of the plant pot.


Is it worthwhile sowing old seeds?

If you find unopened seed packets at the back of the cupboard they may be worth trying even if out of date, although germination rates will not be as good as with fresher, younger seeds you may get a few that grow.

You can easily check if the seeds are viable, and it’s another gardening exercise that your children or grandchildren may like to do. Full details of the process are in the seeds and seed sowing blog. Seed viability is one of the topics we explore in the Edible Garden  gardening lessons course where we help you to grow your own fruit and vegetables.

testing seeds for viability - propagation

However, if the seeds look rotted, mouldy or are soft then just compost them (unless diseased).


Is it too late to plant summer flowering bulbs?

No, you still have time but you do need to get planting asap. Summer flowering bulbs include lilies, nerine and ornamental alliums. You may have bought these in the autumn or earlier this year.
lily 'muscadet', oriental lily, white

If you plant flowering bulbs in pots rather than the border you get greater flexibility with how to use them. This is especially useful with taller flowers such as lilies. Place the pots in the border when your lily is flowering; you’ll gain height in the border and fill in any gaps that earlier flowering perennials have left.


I want to be an organic gardener – how do I prevent black spot on my roses?

If black spot is a problem for your roses, try companion planting to reduce the problem. Chives, Lavender and Nepeta (catmint) are all beneficial. Tidying up all the old leaves from around the base of the rose shrub helps to prevent the fungal spores from overwintering.

Greenfly – I’ve certainly seen plenty of this little aphid already this year. If this is your rose problem, why not encourage ladybirds? They are a natural predator for greenfly.

rose 'tess of the durbervilles', red rose, deciduous shrub

A less chemical approach is better for bees and for humans, but one thing to remember about using predators is that they will not totally eradicate your pests because the predators need a food supply and the pests are exactly that. Using biological controls does maintain a healthier garden overall, and the reality is that even using all the chemicals available, they’ll still be an aphid or slug sneaking in as soon as your back is turned.


How do I bring my dahlia tubers into flower?

Dahlias: if you’re growing these from an overwintered tuber there should be signs of little green shoots. However, if there aren’t, is this because the tuber is still dry and in the dark? If so, before planting your tubers, try sitting them in a container so their roots are in water; and place this in a light, warm environment. You should see new roots and then small shoots growing within a week or so; then you can plant the tubers in free draining potting compost (growing media). Keep them warm, watered and in the light, for example in a greenhouse or conservatory. If you’ve bought dahlia tubers from the garden centre you can use the same technique to break dormancy.


Did you know that you can increase your dahlias by taking cuttings from these new shoots? This is just one of the propagation techniques we cover in the intermediate gardening lessons course.



If it’s raining heavily when you’ve set aside some gardening time, and you don’t fancy being in the garden, you could always check on your house plants. If the roots are showing through the bottom, it’s definitely time to re-pot!

house plant with roots poking through base of clay pot, needs re-potting

Enjoy your garden, this weekend, during National Gardening Week 2016 and all year round. And if Plews can help you achieve the garden of your dreams with gardening lessons, garden design, planting design, garden landscaping or a garden advice visit, do get in touch, we’d love to hear from you.


Related gardening blogs you may enjoy

Peat free compost – are you still confused?
Choosing your Greenhouse
Allotments and Allotment Gardens
National Gardening Week 2015

Pippin, seed packets, tabby cat, seeds, grow your own, propagation

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garden designer, gardening writer, gardening teacher, garden advisor

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