Every week I email a gardening question to the panel of experts at BBC Radio Norfolk’s The Garden Party and then eagerly listen to the programme the following day, scribbling down the gems of information they kindly offer. Sometimes Laila sends a question or two as well. This is a transcript of the advice that The Garden Party experts gave us on this week’s gardening challenge!
We’ve got a bay tree in a large pot but I’ve noticed the leaves are a yellowy-green colour and have been for some time. Does this mean it needs feeding?
I’ve often heard Alan Gray and Ian Roofe mention adding Fish, Blood and Bone to feed plants in pots – sprinkling it on and forking it in… Well, I’ve been given a large box of SEAWEED ENHANCED PLANT GROWTH STIMULANT. Will this do instead?
If so, how many times a year should I do it please?
(BBC Radio Norfolk’s The garden party is presented by Thordis Fridriksson aka @thunderfairy and Alan Gray from East Ruston Old Vicarage with this week’s guest, botanist and garden expert Richard Hobbs.)
ALAN: From the photograph you sent Bridget, I think that your bay tree looks perfectly healthy because that is the colour of bay leaves – they ARE a yellowy green colour, an olivey-yellowish green actually. Of course you can and should feed it if it’s in a pot. Two things however that I don’t like the sound of about your large box of plant growth stimulant though: one is the word enhanced and the other is the word stimulant…
THUNDERFAIRY: I would have though both of those words would have gone down very well with you!
ALAN: It just makes me wonder what else might be in it… and growth stimulant can mean many things can’t it…
RICHARD: Such as hormones…
THUNDERFAIRY: Okay, so if you are looking for something good for all of your plants in pots, what would you recommend? Would it be fish blood and bone? Would it be seaweed feed? What would it be?
ALAN: Well, I’m a great lover of an organic seaweed feed which I put on plants that don’t need re-potting every year. I put about a teaspoonful on the top and just scratch it in a bit and then as you water the plant from the top, each time it gets a little dose of fertiliser.
RICHARD: But I think you’ve got to be careful here but you’re at risk of suggesting that you can just do feeding and topping up, feeding and topping up… but there comes a time when you’ve actually got to get rid of that old compost and start all over again.
THUNDERFAIRY: And how often is that?
RICHARD: Well, as often as you can. Ideally it wants to be done annually but I would say it must be done every third year. You need to get that Bay out of its pot and remove all the old compost, a job for the pressure hose! You can treat it quite roughly, shake it around a bit and even kick it because you get dead bits on the roots just like you do on the rest of the plant and you need to get rid of them. And then re-pot it – it doesn’t need to go in a bigger pot – in fresh compost. The reason you have to do this is that when compost gets old, it loses its structure. All compost needs to have particles of different sizes so they can hold water and air ….and as the compost breaks down into very small particles, you end up with small holes that only hold water but are not big enough to hold air and without oxygen you can shove as much food on the top as you like but the plant can’t take it up effectively.
ALAN: In my opinion you have to be aware that plants have a finite life in pots – they can’t live in them forever, so you have to take that into consideration and weigh up the pros and cons.
THUNDERFAIRY: Well, I hope that answers your question Bridget. Good luck with your Bay tree!