I don't wanna make coke. I wanna chew coca leaves and make coca tea. They sell boxes of coca tea bags on several web sites, but I'd rather grow it myself.
You don't need a rain forest if you grow indoors. Or if you live in topical or sub-tropical and can protect from frost.
Some info I found:
1. Seeds should be planted as soon as they fall from the bush. If they dry out, they will die right away. The only way to keep them for a maximum of about two weeks, is to keep them in moist (not wet) sphagnum in a cool place. Often this initiates germination, so they must be watched for rot or premature germination. Under no circumstances should they be kept dry, since even room humidity is too dry.
2. Vermiculite seems to be the best medium for coca germination, fine grade if possible. Styrofoam cups are OK, but I prefer small plastic pots, 2"diameter, with holes in the bottom. Seeds should be planted no deeper than one inch. Pots should be raised so as not to saturate the medium. Coca, whether as a seedling or a mature plant, never likes to have wet feet. I think it is better to start them in small pots rather than flats, so there is less damage to the root system when they are transplanted. Forget the hot pad -- I think it is completely unnecessary. Seedlings usually come up in 2 to 4 weeks if they are viable.
3. Since most people don't have enough room in their shower stalls for plants, I'd say forget this one, too. Seeds will germinate in any warm place, even if the humidity is not too great. A better idea is to place your germination pots in a terrarium with a coarse gravel layer on the bottom. Do not seal over and allow plenty of ventilation if you choose to place a layer of glass over the terrarium. Any box of this sort will do. If possible, place a Growlux fluorescent fixture, with two 40 W bulbs, over the terrarium, especially after seeds germinate. A common problem at this state is etiolation (too little light) which makes the plantlets weak and very susceptible to damping off, a fungus attack of the tender stems.
4. Water the seeds when the vermiculite starts to dry out. Once a day is probably too often, unless you live in a very dry apartment. But if the drainage is good and you have plenty of holes in the bottom of the pots, excess water should drain off. Fungal attack is a real problem in a humid atmosphere and another reason for keeping the plants out of your shower, a basically unhygenic place for plants.
5. Transplanting: plantlets can remain in vermiculite starting pots until they are about 2-3 inches tall. The growlights should be about a foot above the plants. I do not recommend clay pots at this stage. They dry out too fast, especially in a dry apartment. Even in one day, a fast-drying shock can kill your plants. It is better to move into plastic pots, but the size should be increased gradually. A big pot is not necessarily good for a small plant, in fact it is not a good idea at all. From styrofoam cups, I suggest a two-inch pot, then increase 1-2 inches per transplanting.
6. Soil mixture: forget the vermiculite from now on. It holds too much moisture and makes for saturated, unhealthy soil. I suggest the following: 0.25 coarse clean sand, 0.25 perlite, 0.25 sterilized loam, and 0.25 milled peat. If this seems too light, increase loam and peat. Some sterilized organic compost, screened, may also be added for nutrition.
7. Even when the plants are still in vermiculite, feeding with soluble plant food is recommended. They are heavy feeders and every three weeks or more often is not too often to fertilize. When plants are older it is important to give them iron in the form of iron chelate, available as a red powder sold as KEELATE on the West Coast. A yellow powder, not as good, is sold as SEQUESTRENE. This element should be added about every six months, but strictly according to instructions. Soil must be flushed three times after applying the dissolved iron compound to avoid burning roots. Most yellowed or bleached out leaves are caused by iron deficiency, but this also occurs when plants go deciduous. Periodically, the whole coca bush turns yellow and drops its leaves, every one. Most people freak out when this happens, but if it is otherwise a healthy, vigorous plant, then this is normal. After dropping, new flushes soon appear to renew the foliage. This is more likely to happen with Erythroxylum coca than with E. novogranatense.
8. Transplanting depends on the size of the plant and how fast it is growing. If you think your plant needs transplanting, look at the holes in the bottom of the pot to see if any roots are present. If so, then the roots have probably filled the pot and it is time. You can also carefully de-pot the plant by tapping upside down on a table edge. Repotting is probably unnecessary unless the roots have encircled the inner periphery of the pot. Again, the size of the pot should be increased gradually for best growth.
9. Watering: most city water, is unsuitable for coca. They are calciphobes and don't like heavy salts in the water. Best to use rainwater, melted snow, bottled spring water or distilled water if they are available. Plants should only be watered if the soil dries out. Stick your finger in the soil. If it feels moist, don't water.
10. Bugs: coca is amazingly resistant to insects and mites. Mealy bugs are the worst offenders. These may be removed with a forceps or cotton swab dipped in 50-70% alcohol. Keep infested plants in quarantine. Malathion may be used as a last resort, but then leaves cannot be used until the next flush (of leaves).
11 Light: warm, sunny exposure indoors. Full sun (through a window) will not hurt plantlets over 3 inches tall. But no full sun outdoors until they are 3 feet tall. If plants are put out in the summer, they should be protected from sun, rain, and wind, until they are large and strong. Put them in a shady place first, under a tree, etc., end gradually move to a sunnier location. Breezes are good for plants and even indoors a fan on low should be directed towards the plants. It makes them stronger.
12. Plants can also be grown entirely under growlights, or a combination of growlights and window light. Most apartments are not sunny enough for strong growth, so especially in winter, give the plants accessory light. Growlux Widespectrum Tubes seem to work well. I use one Growlux and one regular Sylvania Lifeline tube in each fixture. They work very well. The lamps are suspended 6 inches to one foot above larger plants.
13. Careful removal of the older leaves does not harm plants, but they should be strong and healthy to allow this, and probably three years old if grown indoors.
14. Coca does not like extremes of any kind. 50° F. is the lowest permissible temperature, 90° F. the highest. Sudden temperature changes are especially damaging. Likewise, sudden changes in air humidity or soil moisture. E. novogranatense tolerates extremes, especially droughts, better than E. coca, which is a much more delicate plant, but the one which produces the most alkaloid.
15. Coca cuttings root very poorly. I have managed to root some E. novogranatense cuttings only after six months in perlite with an initial application of Hormodin #1 rooting hormone. It is better to fertilize your flowers and plant seed. Some varieties are self-compatible (self-fertilizing). Others require two plants of different stylar lengths (long styled x short styled) to produce seed. This is routinely accomplished by bees and other insects in the greenhouse during the summer months and can be done with a fine artists brush at home, merely by dusting pollen from flowers on one plant to those on another with opposite stylar form. In California, outdoor cultivation of coca is possible only around San Diego, if there. Trujillo Coca would probably do well there under irrigation and intensive care. Elsewhere, forget it. I do not subscribe to growing it commercially indoors and doubt if the produce would be worthwhile. Greenhouse and apartment grown leaf is very inferior in flavor and potency. Fresh air and sunshine are in order (as with Cannabis).