Click here to view details of our previous Q&A sessions.

Name: Dave Christian Senior
Question: Hi sue ive just got one of those LED red and blue lights to help young plats to grow it's 400cm sq. I have a 8 x 6 greenhouse is this all right.how close dose the light need to be ie; to seed trays and plants. Sure you can help me, thank you.

Answer: Hi Dave, it’s important to note that only the plants directly underneath the light will benefit; any placed outside the 400cm square area will receive a reduced light intensity so may not grow as effectively. Red and blue LED lights should be suspended about 30-60cm (1-2 foot) above the plant foliage for best results - the closer you place them the more intense the light - it may be best to experiment with this to see what works for you. However be aware that placing them closer than recommended may be detrimental to your plants.

It’s also very important to make sure you give your plants a break at night and turn the lights off! Really the lighting should only be supplementary and switched on at the beginning and end of the day to extend the light hours. Natural light will be sufficient throughout the day. It’s handy to buy a timer switch to save you going backwards and forwards each morning and night.

The last thing to be aware of with lighting is that different plants can respond to different light levels. With some plants a long day length tells them to flower (summer bedding plants), whereas other plants flower when day length gets shorter (Chrysanthemums). Many are not affected by day length at all but it may be worth thinking about, depending on the plants you grow.I’m not sure if you’ve considered the temperature in your greenhouse but do make sure it’s warm enough, as the lights won’t be as effective without heat for the plants to grow. I hope this has helped get you started and good luck with the growing.


Name: Kevin Joseph
Question: I have a 10 year old camellia however the upper leaves are looking yellow. Ive given it some iron awhile back but it doesnt seem to off helped. also i had to picked some infected leaves of so its looking a little bare, will new leaves shoot though from the side of the branch where i removed them?

Answer: Hi Kevin. Yes I remember your Camellia. You were concerned about it back in July. It sounds to me as though it has become rather sparse and unsightly, which is fairly common in mature Camellias.

The most effective way to rectify this is to hard prune it in early spring by cutting stems back to about 60cm (2ft) above ground level. I know this sounds drastic, and many other plants would struggle to recover from such treatment; but Camellias are extremely resilient and actually benefit from rejuvenation pruning.

After pruning, spread a thick mulch of well rotted manure around the base of the plant to feed the roots and conserve moisture in the soil. Take care not to mound it up around the stem though! Make sure that you water the camellia regularly from now on - you may want to install a trickle irrigation pipe to make this task easier.

Be warned that you will probably not see new growth from the remaining stump until midsummer when a proliferation of new shoots will appear. Thin out the new shoots as they develop until you have a nice new framework of stems for the plant to regrow from. I should also mention that by pruning the plant in this way you will be forfitting any flowers this spring. However your plant will look so much better the following year so it is worth the sacrifice.

The crown is the most sensitive part of the plant and if not protected may have succumbed to the harsh temperatures we’ve been having recently. The best thing to do is protect the crown now and in late spring look out for the new fronds (hairy brown bumps). Good luck Sarah and let us know how you get on.