HOW TO GROW BOTTLE PLANTS.
The safest thing to put in is charcoal, which is so light in weight that it cannot crack the glass. If you use small pebbles such as pea gravel, do this with care, perhaps a thin layer of peat to cushion the impact of the stones on the glass base. To fill a carboy, make a funnel or cylindrical chute of strong paper or card. Insert one end of this into the neck of the jar. First pour in the peat, then the gravel and lastly the soil. This drainage layer needs to be quite deep, 2 inch or so for a large carboy and proportionately less for smaller jars. Composts should not be too rich or the plants will grow too fast. The amount of soil you use will depend upon the size of the container; you should be able to see much more glass and plants than soil but it is the depth of the plant’s roots, which should guide you. These must be properly planted. To get the soil in the right condition so far as moisture is concerned, calculate how much you need, take about one third of this amount and spread this out on newspaper to dry. Spray the other two thirds until it is just moist, uniformly so, and when you take a handful and squeeze it gently it should just cling together. This dampened compost should go in first. The dry compost follows to form a top dry layer, which should help to seal in the moisture. As with dish gardens, water the plants beforehand and allow them to drain thoroughly. Knock them from their pots in turn. If the aperture of the glass is very small it may be necessary to shake off any loose soil from the roots so that the plant can be slipped in easily. The leafy portion is no problem because this naturally contracts, as it is eased root first through the opening. To make sure of this, hold the plant by the tips of its leaves, or if it is tall, gather its branches or leaves up near its center stem, so that this top portion is made really slim. Make a hole in the soil, tilt the jar and aim for the hole. This actually, is easier than it sounds. Direct the plant into the hole with the stick or with the spoon. Make the hole for the next plant directing the soil round the roots of the first plant. Settle the soil down before tilting the jar for the second time. Continue this way until all the plants are in position. If the soil is properly moist the plants should settle in and you should not need to water it for some weeks. If the balance is right you should see a little condensation or dew on the interior each morning. However, if this seems excessive then there are several runnels and large drops on the glass, there is too much moisture in the soil and it would be prudent to remove the moisture from the glass to prevent it running back into the soil. Lash a tissue to the end of a wire or the bow of a coat hanger to do this. When the time comes that you see no condensation, this is an indication that the soil needs watering. To do this, gently spray the interior glass. This will help to clean it at the same time. Do not feed the soil or the plants will grow too well.
