Repotting a Lemon Tree

[Lorraine70]

A couple of weeks ago I bought a lemon tree from Aldi. It's doing very well in my sun-room, but I'm wondering whether or not I should re-pot it? There's not much room in the pot for watering, only a couple of centimetres so watering is very difficult!

I've done a bit of research on-line, but am still unsure. Some sites recommend ericaceous compost but others say not too, others say use John Innes#3.

Can anybody help me?

[starloc]

I wouldnt repot yet, its not warm enough, they need to be rapidly growing to repot, the soil in the pots isnt that good but watered corectly the plants will be happy a long time without repoting

Do not water them from the top , let the compost dry out nearly to dust about 2 inch down ( the moss on the pots will look dead! ) , and then fill a bucket with slightly warm water ( about 30c ) with citrus fertiliser, and then lower the pot into it till all the bubbles stop, try not to get the trunk of the tree wet! to prevent rot, the water will soak upwards to the top layer, dont leave it in the bucket for more thsn 5 to 10 minutes, then take it out and let it drain well, buy leaving the pot raised up from the surface till it stops dripping out

When you repot the plant will grow fairly quickly, but will not flower as much till it fills the new pot.

Only go up a tiny bit in pot size, if at all, the ones i bought last year are in the small hight morrisons flower buckets, they are about an inch bigger than the pot they came from aldi in, you need to chop lots of drainage holes in the bottom and the sides at the bottom
in june i took them out of the pot from aldi and used a sharp kitchen knife, chopped the outer 1/2 inch from the sides and bottom of the root ball, scraped it slightly till it was rough, knocked the top layer of soil with the moss on from the top and then repotted in a mix of the soil from the pot ( with most of the roots removed ) and a handfull of b+q soil, a handfull of perlite and a handfull of b+q growbag compost, just put some of the mix in the bottom and put the plant in and poke it around and put compist back on top, leaving the top surface of the roots just visable, dont bury them

Its best to use very free draining compost if your changing it all ( unlike what they are potted in ) , use something like

30% horticultural grit, 30% sphagnum moss ( the hanging basket type ) and 1/3 bark chips ( the type used for orchids, not the garden mulch )

or a compost sold for citrus, mixed 70/30 with perlite

or , i have used things like 30% b+q soil, 30% b+q ericacious compost and 30% perlite

you can use coconut husk chips but they need treating before using with variaous chemicals to remove salts in them, so its a real pain and i found plants need watering too often when in coconut husk

Myself im not repotting the ones i got from aldi this year for another year or so, i just need to be carefull to let them dry out well between waterings as the soil doesnt drain that well

[Lorraine70]

Wow, Starloc, thank you so much for your reply! At last, easy to understand and clear instructions. I'll take your advice on board and not repot this year, and will follow your instructions on watering. I'll print off your response and keep it for future use.

Once again, many thanks.

[chilliking]

lots of infor above.

i bought a lemon tree from a local nursery last week. it was in quite a small pot and i was advised to repot in a slightly larger pot with a mix of JI no 3 and multi purpose compost. plenty of crocks in the bottom to aid drainage and place it in my heated conservatory to maximise light until it is warm enough to go outside.

it seems ok so far - i'm no expert though!

[starloc]

putting anything in the bottom of the pot can cause a lot of problems, you create a perched water table within the pot actualy causing the compost to stay wetter even though it should drain better it doesnt

What happens is the water runs down and when saturated will run out of the pot fine, but as soon as its not totaly saturated (to the point that the weight of water pushes the water down) air gaps form below the damp compost, the air bubbles prevent water moving downwards so preventing the compost draining , stagnent water forms and the roots will rot , its all about the surface tension of the potting media

Ji no3 will work, but it does stay too wet so its best mixed with some gravel or perlite to let air in, perlite works better at holding air in the pot, its not over watering thats the problem its lack of air to the roots, the roots need oxygen to work and prevent them rotting


Be carefull at this time of year while the sun is strong and the temperature is colder, direct sun on the leaves while the pot is cool will cause major leaf drop, keep an eye on the compost temperature if you have bright light on the plant, if the pot is cold keep the tree with no direct light

[Hillwalker]

putting anything in the bottom of the pot can cause a lot of problems, you create a perched water table within the pot actualy causing the compost to stay wetter even though it should drain better it doesnt

What happens is the water runs down and when saturated will run out of the pot fine, but as soon as its not totaly saturated (to the point that the weight of water pushes the water down) air gaps form below the damp compost, the air bubbles prevent water moving downwards so preventing the compost draining , stagnent water forms and the roots will rot

Interesting post, starloc. Not heard this drainage view before, is it based on your own experience and/or that of others? Can you provide links to similar views?

[starloc]

theres loads on info on the internet about it, particularly on websites about things like citrus, orchids etc that have root rot problems

about halfway down this page from the university of Florida ( 4th paragraph below figure 3 )

BUL241/CN004: Growth Media for Container Grown Ornamental Plants

and just another i found

The new way to succeed in container planting - Dry Heat Gardener

[Hillwalker]

Thanks. I'll give them a read.

[Hillwalker]

about halfway down this page from the university of Florida ( 4th paragraph below figure 3 )

BUL241/CN004: Growth Media for Container Grown Ornamental Plants

"Some have suggested the placement of gravel in the bottom of containers improves drainage. In fact, the gravel decreases the total volume of medium with favorable aeration. The pores at the interface of the container medium and gravel must be saturated before water will move down into the gravel. This means that a layer of medium with near maximum water content is positioned above the gravel rather than on the container bottom."

Interesting read. I take the point about the bottom of the compost medium needing to be saturated before water flows downwards through the gravel. Although, this also applies to compost/soil sitting on the bottom of a container, it also has to be saturated before water will flow through the holes, so I fail to see the difference. In fact, I would suggest that having some aggregate at the bottom would help alleviate saturation by allowing air to circulate underneath this wettest area.

[starloc]

The problem of the gravel in the bottom is is that, the deeper the potting mix in the pot as long as it lets lots of air through, the more room there is for the root system , roots will not grow in saturated soil as they need oxygen so the more air the better
If you add gravel or similar to the bottom then the water level rises in the pot leaving less air filled soil in the pot for the size of the pot, and more room for the roots to try and grow into where they can not grow due to lack of oxygen
Because gravel can not wick the water away from the compost it elevates the water level up the pot, the reason for the problem is due to the difference in size between the sizes of the compost particles and the gravel particles
A very gritty free draining mix right through the pot is best

In a very rough surface such as gravel against the compost on one side and the pot on the other the gap is large enough for a bubble of water to form that prevents it running out of the pot through capiliary action, capilary action doesnt work if the gaps between the surfaces are too large giving a large surface area of contact with the water, you get better capiliary action between a flat surface ( bottom of pot ) and the compost surface that is shaped to the pot with good contact

This can be seen if you get 2 pieces of wood, hold then together and put some water between the pieces and it will seep through , leave a slight gap and the water will form a `bubble` between the 2 surfaces and not seep through, close fitting parts seep water faster than a slight gap

some more links about it

http://www.al.gov.bc.ca/ornamentals/...e/aeration.pdf

http://davesgarden.com/community/forums/t/527353/

[chilliking]

interesting stuff starloc - u got me worried now!

my lemon is in a south facing conservatory but behind where the blind bunches when open so should avoid direct mid day sun while still getting plenty of light. i leave the heating on at night so it won't get too chilly.

fingers crossed my potting doesn't harm it though!

[Hillwalker]

Hi Starloc,

I've not been well for the last week and haven't been able to continue the interesting (to me at least) point about container drainage.

Having looked into the research on this subject and recollecting my own experiences I have to concede with your point of view. Where I think it becomes less clear as to the best option is with poorly designed containers that have inherently poor drainage.

In future I'll return to my previous ways and 'compost' fill to the bottom of the container.

[old grumpy]

Lemon trees

i put a lemon pip on some moist kitchen towel and it germinated in about 2 weeks (6 months ago)and now its 18" tall and re potted in Citrus compost from Garden center and is growing rapidly in my greenhouse....how long before they flower and fruit...?

[starloc]

It can be ( usually is ) a very long time, and even longer if you ever prune it!

As it grows it will count up the leaf nodes grown and when it has grown enough it will start to flower, about 10 years.....and 12 foot high

They make a great tree till then though, they still smell of citrus and you can eat the leaves

The problem in most countries is the weather, you need to keep it protected in the winter

[Ben1030]

I've got some citrus compost, perlite and some John innes 3 left over. Would that make a good mix?