Any citrus afficionados?

[ourarka]

My citrus don't appear to happy this year. To give you the background, they live in containers in a sheltered brick 'alcove', covered by polycarbonate to ensure they don't get overly wet, and maintained frost free in winter (find it drastically reduces the amount of fruit munching caterpillars that appear - not that there was any frost to speak of this year!) They have always been very happy, and to be fair started this year well, good leaf growth with plenty of flowers. I have neglected them slightly, though still kept well fed/watered well but on inspection today they aren't looking in the best of health. Any thoughts anyone? They are labelled below but I have a decent size calamondin, tahiti lime and smaller Meyer lemon.

[Kirk]

Check for scale insect, I find they get those easily and they weaken the citrus.
The other is vine weevil, which you might miss if they are semi-outside.

Do you let them dry out a reasonable amount before watering?
I always wait until mine have a fairly dry surface.
They are after all from hotter and drier climates then the UK.

[starloc]

Its difficult to get a close enough look but on the last 2 it does look like spider mites,

The yellow tips on the leaves could probably be manganese deficiency, if not using a good citrus fertiliser this will happen, many fertilisers sold as citrus fertilisers are short on micronutrients

How long have you had them? how long in the pots they are in now? what compost? What fertiliser?

It could also be damage from lime in cement if the water that drips on them comes down the walls, doesn't look that much like that though, but the lime will change the pH of the compost eventually

Main problem does look like it could be spider mites on the last 2 photos

[ourarka]

Its difficult to get a close enough look but on the last 2 it does look like spider mites,

The yellow tips on the leaves could probably be manganese deficiency, if not using a good citrus fertiliser this will happen, many fertilisers sold as citrus fertilisers are short on micronutrients

How long have you had them? how long in the pots they are in now? what compost? What fertiliser?

It could also be damage from lime in cement if the water that drips on them comes down the walls, doesn't look that much like that though, but the lime will change the pH of the compost eventually

Main problem does look like it could be spider mites on the last 2 photos

Thanks, spider mites could be an issue and I have had scale before so will have a good look. Normally use a citrus fertiliser so probably not that.

The lime and calamondin have been in their pots a little while now (2-3 years) - is it worth a change?

Also, this year I have packed that area with plants. Given that it has been a humid summer, is it worth me reducing the amount of plants to give a better through flow of air? Also, the backs of the plants face the wall, so don't get any sunlight - would this contribute to die back?

[starloc]

Lack of light may cause dieback, but citrus are undercanopy plants so don't need much light, they like lots of light but don't need it.

Lack of air circulating isn't usually a problem apart from things like spidermites by being too dry, citrus leaves like to be wet by the rain, rain on pots isn't usually a problem as rain water contains oxygen, but in very heavy rain for long periods its best to cover them.

Don't repot at this time of year, they can stay in the pots for years but always grow better after repoting , but only every few years or so unless you want a massive plant, leave it till the plant is starting to grow next year, after growing a load of shoots repot and its roots will grow to fill the pot, only do this in late spring early summer, citrus need to be repotted in full growth unlike most other trees. when repotting next year the best way is to never untwist the roots....chop the outer 1cm off the sides and bottom of the root ball with a sharp kitchen knife and then use a slightly larger pot and fill the gap with a decent potting mix, never add anything to the bottom of the pot to try and help drainage

The citrus fertiliser, its still best to add some other micronutrients, such as occasionally spraying with Epsom salts, check the citrus fertiliser carefully as many are no good for citrus!, good ones I have seen are are by chempak, global orange groves and the citrus centre , none of the others I have looked at have had the required micronutrients, however I am now using separate components such as sulphate of ammonia etc from the garden centre as its so much cheaper, to ad micronutrients I add a bit of magnesium with Epsom salts and the rest with a slow release fertiliser that contains them all,
Generally I find that one of the multi colour slow release ones is the one to buy check it has many micronutrients such as molybdenum, manganese, magnesium, copper etc, add it to the surface of the pot or when repotting and forget its there, still fertilise with the same level of citrus fertiliser as well
If using tap water always leave it to stand overnight before use and if cold warm it slightly, then add a tiny drop of white vinegar to acidify it slightly, then add fertiliser

The dieback is probably spider mites, it usually is! , but can also be lack of micronutrients or root damage from overwatering ( usually from sitting in a saucer of water at the bottom )

[ourarka]

Thanks Starloc, that's a great post - very informative and I'll be sure to keep a check on the fertiliser. Can't remember the brand off the top of my head but will look on to it.

Today I hauled the four plants out and gave them the standard poorly plant treatment - spray with hose, cut off dead/dying bits, replace top 1" compost, spray with Provado. I am going to bring them out in to the open for the rest of the summer, and keep them there next year, only using that area for overwintering. I still think they have been cooped up a bit, not exposed to the weather that they probably enjoy in spring/summer (and the critters not so much!)

The pictures are of them now I have hauled them out (apologies if they're on their side - not sure why). The smallest one is an unnamed citrus that I picked up for pennies at a garden centre. The final picture is of the area that they have been living, and will spend the winter (unless it gets bloomin' cold)

[starloc]

Be careful with the compost at the top, the top roots are the important ones, feeder roots, they are always best left alone and a bit exposed, just visible , never bury them deep, jut sticking out of the compost on top edges

Winter temperatures, If outside I would close the front as well, and in very cold weather a 100w old style light bulb to keep them warm, lime and meyer lemon trees don't like the cold as much as some citrus

The smallest one is probably a lemon, if you have a close up of the leaves it is easy to tell lemon lime orange calamondin grapefruit etc from each other ( just not exact variety ) due to the shape of the leaf and the petiole

The pots they are in only have drainage holes at the bottom, make sure you lift the pots up off the floor

[ourarka]

Great stuff again starloc - I certainly didn't know about the feeder roots. Ill also search the leaf types so I can find out what the small one is.

Pots aren't raised but on a fairly undulating patio so don't foresee any water pools forming as they drain.

I would always keep an eye on winter temps. If anything more than light frost forecast (and that area stays a couple of degrees warmer) them they come in to the conservatory temporarily. If I keep them inside all winter I find the caterpillars have a field day, never mind the space issue.


Sent from my iPhone using Grow Your Own Forum