Citrus need 2 feeds: one mid spring – when soils have warmed, and one mid summer.
The last, mid summer/ January feed is really important for young trees, to inspire strong growth while its warm, boosting them to be a little bigger and bolder before they take on winter.
Natural feed
The very best stuff to use to feed your citrus is natural stuff that the soil knows and readily assimilates. Homemade compost, well rotten manure, vermicastings, fish waste or seaweed are my top picks. Artificial fertilisers and/or overfeeding (whether natural or otherwise), is one of the main causes of citrus pests and disease.
Apply the feed either on top of existing mulch if its well broken down, or if pretty raw, pull the mulch back before proceeding. Spread a fine layer of compost + a few spades of either chopped up kelp or well rotten manure or vermicastings.
Mulch
Mulch is key, especially for citrus – they must not dry out! Mulch holds moisture, builds humus, encourages a thriving soil life, moderates temperature and reduces weeds/ grass that compete – so much goodness here.
The best mulch is a mixed woody one, but any stalky stuff will do. Do your best to create a mixture – diversity is the answer.
Forage in your community for sea-wrack (the woody mix on west coast beaches after a storm), crunched up bracken fern, leaves, the scrapings beneath the firewood pile ….
For some extra goodness, snuggle a lump of wood into the mulch and leave it to rot down. A great use for those too hard to split knotty bits of firewood!
Water + Ola pots
Citrus must not dry out – if they do, the fruit wont be plump and juicy, nor will the tree be hearty and strong. The best way to achieve this is by building strong, humus rich soil. Soil like this holds water for a goodly period of time. Check in weekly with the soil beneath citrus during summer and autumn, and if its dry, give it a soak. The ideal condition is barely moist soil – neither dry nor wet.
Ola pots, are a super cool, very old technology – they’re unglazed terracotta pots with a lid that you bury beside your tree/ shrub/ plant. Water is drawn out in a capillary action as soils dry – super clever! Top them up as required. If you cant find any to buy, they are easy to make. You tube will happily show you how.
Biological spray
Keep citrus strong with a monthly biological spray through the warmer weather. Up the ante to once a week if trees are poorly or pest laden – liquid foliar feed is an immediate way to get nutrient into your trees.
Trouble Shooting
Citrus success begins with a variety that suits your place and a well chosen location. No matter how well you feed and care for your trees, if the location does not cover basic citrus needs or the variety is poorly chosen – the trees wont ever be glorious.
When things go awry eg: pest/ disease/ all round not looking very handsome – your very first port of call is the soil. Do a DIY test and go from there. Soggy soil, dry soil or hungry soil mean mineral exchange is poor + biology absent, setting in motion the cascade of poor health.
Hi Kath. Thanks for the citrus tips. I am new to the care of citrus trees having only just purchased my property recently. I have been away for a couple of months and have come back to find my citrus covered in borer holes and some have small white eggs all over the branches. In another blog you mentioned injecting kerosene into the holes. Is this ok if you are trying to keep your trees organic? I was also told to use neem oil and got some organic eco neem but when I read the closer instructions it says not to use it on plants with edible fruit. Very confused as to how to treat the pests without toxicity and organically. Any suggestions?
Yes it is confusing! The Neem I recommend is naturallyneem.co.nz – no withholding period. Neem is not a contact killer – it works when its ingested which means the grubs will need to eat it for it to work. That means you’ll need to spray the wood around where the eggs are. Neem is awesome – I’d def give it a go. Even if it impacts a few it’ll be worth it. You’ll need to spray as often as you can – perhaps weekly, as you wont know when they will be hatching.
Kerosene is the perfect thing to knock those grubs out ok so get it into those holes! Dont prune your tree at this time of year as the adult borers are out and about and the fresh pruning wound creates the perfect place for them to lay their eggs. Lemon trees will live alongside some borer so as long as you keep up with injecting the holes and plugging them – you’ll keep it managed. Support your tree with all the things I mentioned in my blogpost to keep it in top health and all will be well 🙂 Kath
Hi Kath
Thanks for all this helpful stuff!
My question is how to use the fish heads and guts: dig them straight into the soil near the tree? Or bury them in the compost? Or something else?
Either or works perfectly Miranda 🙂 Dig some into the ground and every now and then have a look to see the miracle of decompostion happening and all the worms and life that come – its amazing!
Hi Kath. The discussion around our table right now is whether its 2yrs in our garden, or two years from when the seed was planted? Ie do i go removing all the fruit from my citrus which i planted last year or not? They look more than 2yrs old to me!
I’d be removing them still – remove fruit for 2 years from planting … atleast. Although it depends on how big the tree is overall Jane. The idea is to let the tree put its energy into roots, trunk and canopy for long term strength. Growing fruit takes alot of carbs, leaving not much for tree growth at this young stage. The longer you can hold off on fruit production the better your tree. Patience grasshopper!
Hi. We have kikuya grass & just covering over with wet cardboard/newspaper, compost & mulch, the kikuya & oxalis continues to come through.
So if I was to try to clear the areas under the orange, lemon, grapefruit trees, to help them & possibly even create a companion lay under, what should I do?
Yes the card and mulch doesn’t get rid of them instantly, it takes time for the soil to change and the weeds to move off. Keep on covering them is the best way and try to regard with less distaste also helps though its not always easy I know! A companion layer beneath citrus is only good if your trees are tall and have a big gap between the lower set of branches and the ground and you live somewhere hot with low rainfall, otherwise the companions block airflow and you invite another set of problems along. If it was me, I’ be sure to have a lovely pile of ramial woodchips nearby (mulch from the tips of branches – either made yourself or the guys working the lines create)and a stash of card so that whenever the kikuyu grows in force its easy to slash it back and put another layer on top.
I hate kikuyu. It keeps spreading between my garden beds (next door was a building site for 2 years) and I keep forever pulling it out instead of weeding the bindweed out of my garden beds.
It doesn’t seem to spread under my fruit trees, yet?, I have loads of nasturtiums there.
Kia ora Kath, Happy New Year to you.
I am wondering if you’ve got any advice for a couple of citrus issues In having…I have a lime tree that’s doing well, but the leaves are showing a persistent manganese deficiency: there are many ‘cures’ online, but all seem to involve buying something of a chemical nature and mainlining the tree with it – I’d really prefer a natural alternative. We are in Kapiti and generally have sandy soil, though I’ve been adding lots of compost and much for a while now and the soil has improved heaps.
Another citrus dilemma is a blood orange tree with really weird leaves, curled and bumpy- looking like spinach leaves… I’ve asked friends who garden but we’re all baffled.
Thank you so much 🙏
Hi Lela, cut straight to the chase and get a soil test done ok. Theres obviously a serious soil issue on the go. Otherwise its a definate case for a garden coach session with me as theres too many possibilities and I’d need to eyeball the tree and we’d need to look at the whole system + a bit of history. All the best K
Hi Kath! I have an indoor lime tree. Ita probably about 30 inches tall. There is a lot off flies on my lim tree and other plants in the house. Do you think neem oil will help? If so, do you reccomnd spraying every week? I also love what you wrote abouy using compost to feed your cirtus plant. Do you have suggestions on what to use for my plant and how often i would need to feed it?
Depends what flies you speak of – if you mean little white flies then yes it will! Inside is always harder because theres no beneficial insects – so you need to take on their role and pay regular attention. Full spectrum mineral fertiliser, watering just right – not too wet or too dry, dilute liquid feed + neem as often as weekly sprayed on the foliage in the cool of the evening. Keep topping up the compost. Pluck off all flowers and fruits until it has a big enough canopy. My hubby is growing beautiful citrus in our sunny bathroom in pots – glossy dark green leaves from all his undivided attention! Good luck!
Hi, half of the grapefruit is green and gloss6 with 4-6cn fruits. Other half leaf is yellow, fruits 2-3cm and some fruits dropping. Any suggestions?
I have not folio fed with seaweed 100:1 dilution yet. The tree is very established and only about .5 m off the ground. Last year produced amazing crop of fruits. Not too sour. Just perfect.
Thankyou kindky
Your first port of call is to check the soil. Every problem. Every time. Check the soil. Dry – it sounds like to me or could just as easily be too wet. Hungry also a high possibility. Start with the soil and go from there.
I enjoy your posts.
What do you suggest for citrus planted in the chicken areas? Bit trickier to get the mulch to stay in place.
Thanks
Impossible even 🙂 I’m sure you can come up with a cunning plan in accordance with your situation – a mobile fence that can easily be erected during hot dry months? a living mulch groundcover the chooks aren’t that interested in? a large square of carpet laid over the mulch?
Thanks Kath,
In the interim I took your idea of wood and created a firewood circle around the lemon then filled it in with great rotted manure and mulch and then leaves and the chooks haven’t touched it.
perfecto!
Hi Kqth,
We have quite an established citrus garden, could I dig Olla pots in or would it disturb the roots too much? Also where do you buy yours from?
Yes you can – the tree will rebuild new roots without a worry. I got my olla pots many many years ago and am out of touch with where so cannot help sorry and will have to leave you to discover this yourself.
Hi Kath, thanks for all your work! Here in (organic) Paekakariki on the sand our old lemon tree (1960’s apparently) has maidenhair fern growing underneath.. I was weeding out wildling spuds growing through the maidenhair today and realised it’s now quite a tough mat. The lemon’s fruit load is pretty light. Together it’s a nice look but now I’m wondering if the maidenhair is stealing nutrients? This includes diluted pee BTW. I’m adding compost from our bins twice yearly.; feeding tomorrow. What are your thoughts please
Hi Tilly! Lovely to hear from you. First I’d be checking the soil, and if its dark and loose and yummy then perhaps they are working together but I fear your intuition is right on. Its hard to imagine those ferny fibrous roots doing your citrus any favours. Citrus have shallow feeder roots so do best with companions that are more team player than dominatrix 🙂