Of all my eclectic collection of indoor plants, the one that gives me the most pleasure is without doubt my Bearss Lime. There is something incredibly decadent about being able to just reach out and pick a piece of fruit without even having to leave the comfort of my own home. In fact given the choice of having Nicole Kidman lounging in my sun porch or my luscious lime I would be hard pushed to make a choice. (OK, I’ve had a moment to reflect and the lime tree has to go.) Hopefully I will never find myself placed in such a difficult position in real life.
The pleasure of rearing miniature citrus trees indoors goes far beyond just avoiding the necessity to wander into the garden every time I feel like a slice of lime to accompany my Mexican beer. Citrus trees are beautiful to look at and they bring with them a wonderful fragrance that permeates the house with a delightful fresh odor.
The bliss of having indoor citrus trees was first brought to prominence in the Renaissance gardens of Italy. The magnificent orangery in the Palace of the Louvre in 1617 was soon copied by Louis XIVth at Versailles and could accommodate 3000 orange trees. After that having an orangery became a must have status symbol among the rich and the indoor citrus garden was here to stay.
A little about light
I am guessing now, but I imagine not everyone reading this article is going to be the proud owner of a huge orangery. If that is the case don’t despair. If you have a conservatory, glazed porch or even a little space on a windowsill in front of a south facing window then a dwarf citrus tree is an option open for you. They do require light and lots of it, however. Five hours of light is the minimum requirement for most citrus so bear that in mind before rushing out and purchasing a tree. Many people like to move their trees outdoors during the summer and this is something that citrus appreciates but if you don’t have that five hours of light in winter and don’t want to invest in specific indoor lighting for plants then don’t go there. If you are able to move the tree outdoors during the warmer months be sure to make the transition gradually so your plant does not die of shock at the sudden introduction to its new surroundings. Whilst indoors turn your pot a quarter turn once a week to give even sun exposure.
Purchasing and Planting
Nearly all dwarf citrus are a grafted combination of a fruiting variety grafted onto dwarf stock. This is important because no matter what variety of citrus you opt for you don’t want to be lavishing your love and attention on a plant that responds to your kindness by turning into a great big tree that takes over you home. If you purchase from a good catalogue or nursery then you will be able to get all the guidance you need. For sheer value for money you are probably best off going for a bare rooted plant though buying a potted plant may make your life slightly easier especially if you don’t have time to pot your new housemate as soon as you get it home.
Choose a pot with at least a twelve inch diameter and as much depth to it as possible. Deeper pots are better for drainage and make the plant less prone to tipping over. On the subject of drainage this is another crucial area to attend to as citrus don’t like to be waterlogged, oh, and they hate being too dry as well. Make sure the pot has sufficient drainage holes then add two inches of gravel before layering with soil based potting soil. Plant your tree leaving two inches below the lip of the pot for watering and taking care not to cover the scar where the graft was made. Add vermiculite for both drainage and to keep the pot as light as possible to avoid giving yourself a hernia when it needs to be moved.
I would suppose that having Nicole Kidman in your conservatory would be quite demanding. A citrus tree would rank only slightly behind that in terms of the attention needed to keep it looking it at its best. In addition to the five hours of sunlight they require, citrus are also heavy feeders and must never dry out completely. In winter they should be watered once a week and every day in summer. It would be worth investing in a moisture probe but if you ensure the soil is never allowed to dry below the top two inches that will suffice.
High humidity is another requisite. This can be achieved with a small humidifier but by placing a watering tray beneath the pot and keeping this filled with water, humidity should be raised enough to keep your plant happy. Place a thin layer of pebbles at the bottom of the tray so the pot can still drain easily.
Like most potted plants there is a need for supplementary feeding and as all citrus are heavy feeders you should expect to feed them once a month with either a specific citrus fertilizer or a high nitrogen fertilizer. Look for the 3-1-1 ratio on the packet.
All this attention sounds more daunting than it really is. Once you have got the hang of what your citrus tree’s needs are it will hopefully reward you with attractive foliage, fresh aromas and the delight of home grown fruit. To let you know it is really happy it may begin to outgrow its allotted space. Don’t let this alarm you. These potted trees are really easy to root prune, and yes, I do know that root pruning is one subject that almost always causes terror for those who have not done it before. It is really not difficult.
In the spring tip your tree carefully from its pot. This is probably the hardest part of the whole operation and may require a little gentle persuasion. Once you have it out of its home then scratch away some of the old soil from around the root ball. You will now find yourself with a fuzzy profusion of fine roots surrounding the thicker feeder roots. With a sharp pair of secateurs cut away most of this thin root material. Aim to lose a third of the root ball but keep the thicker feeder roots. After that simply repot using new potting soil, throw in a small handful of fertilizer and soak well. That wasn’t so hard was it? You can now also pinch out some of the new leaf growth or prune it back to keep your plant growing in an attractive shape.
Unfortunately, the warm humid indoor conditions will not only be appreciated by your plants. There are a few pests who are likely to try to take advantage of the wonderful environment that you have now created. Unlike larger outdoor fruit trees you now have the advantage of a reduced area in which these unwanted visitors can camouflage themselves and so your biggest weapon is careful observation. Spider mite, mealy bug and scale insects are going to be the prime enemy here. Check your tree regularly as all three of these pests specialize in invisibility as their main means of defence. If you spot any then the first method of attack may well be a simple cotton bud soaked in alcohol. Providing you have been searching for them regularly then it is likely that you will catch them before they have a chance to get established. For heavier infestations that have somehow managed to sneak past your radar then you may need to use either insecticidal soap or horticultural oil.
What to grow
Nearly all citrus trees are available in dwarf varieties and it is difficult to give too much advice here as it comes down to personal preference. Most of the oranges bloom in the spring and produce their fruit in the winter. Lemons tend to both flower and produce fruit throughout the year. In my opinion all the citrus trees are similarly endowed in terms of their elegance and beauty which is enhanced by being right in your home at a time of year when that splash of tropical greenery is most needed. I hope that these somewhat complex instructions won’t put you off growing what is a most rewarding group of trees.