Greenhouse Information

TIPS FOR CARING FOR SUBTROPICALS

Ginger

Blooming in late summer, the butterfly ginger, or Hedychium with its heady scented orange, yellow, and white flowers are a great choice for a tropical feel in your garden. Location, location, location is the key with these plants. If you choose to plant them in the ground, where temperatures rarely go below zero degrees Fahrenheit, plant them in a well drained area close to the warmth of your house. If the plants sit in a cold waterlogged area for long, the root system may rot. Heavy mulching, excellent drainage and a south facing wall with greatly increase their chances of making it through winter unharmed.

If you choose to not risk leaving these plants outside, you can overwinter them in the house. After the first frost, but before the first freeze, ginger can be dug up. Cut off the foliage, pot up the root balls, and store them in a cool dry area of your house. Watering is not necessary during the winter, as the plants will be dormant. In Spring, once they begin to grow, you can move them to a warmer location in the house. Wait until the nights are consistently above 55 degrees Fahrenheit before planting them back in your garden.

Tropical Hibiscus

Known for its large brilliant flower, Hibiscus is a relative of our hardy Rose of Sharon. These bushes can grow to enormous size in their native climates. They need to have Zone 9 or 10 to survive winters and will die back to the ground if they get too cold. Tropical hibiscus are mostly grown as container plants, and brought inside in the fall. Preferring filtered sunlight, if you place hibiscus in direct sunlight, the leaves will scorch. They do not do well in heavy shade or in wind. As they have large leaves, they need to be watered at least once a day in hot weather. However do not overwater your plants, as they do not like damp roots any more than they like cold weather. to keep your hibiscus blooming, you should pinch off blossoms after they fade. To overwinter the tropical hibiscus you will need to bring it indoors when temperatures fall below 45 degrees Fahrenheit at night. Make sure that it gets at least 4 hours of sunlight while its indoors so that it can survive. The plant will like some pruning and shaping. While it is indoors it will not need as much water. Check to make sure that the soil is dry before you water.

Contained Citrus Trees

Citrus love to spend the summers outside in a protected spot. Acclimate the tree to full sunlight gradually, putting it in a shady area for a few days first. Once a month feed the citrus with a good multipurpose fertilizer that contains zinc, iron and manganese. We usually have 14-14-14 in the soil. Do not feed heavy concentrations of liquid fertilizer in the winter time as this encourages too much growth. If you need to add soil to your tree container always use a sterile mix with perlite. It should be a light mix, such as Sunshine #3. Only add soil to the same line on the trunk. Leave at least an inch at the top of the pot for watering room. These trees like regular watering. Usually every week to 10 days is enough. When the soil is no longer damp, go ahead and water. Be thorough, but don't drench the soil. Citrus do not like wet feet! A western or southern exposure is the best.

Citrus love humidity. If your living space is dry, especially in winter, mist them frequently. It is also a good idea to put them in a large tray with pebbles, and add water to the top of the pebbles. Do not stand your tree in front of a drafty vent.

Your tree will produce an abundance of blossoms just like any other fruit tree. Not all of these blossoms will produce fruit. You can encourage pollination by taking a soft small paintbrush and brushing the stamens of open blossoms from blossom to blossom. There are not often enough bees in the house to pollinate!

As for pests, spray your tree with horticultural oil such as Neem, or dormant oil following package directions. Your most likely pest will be Spidermites, and the oil will smother them.

Bougainvillea

Your bougainvillea is kept indoors over the winter. As the temperatures start rising in March, you can begin slowly giving it more water. If you need to repot, choose a heavy wide pot with good drainage. Always use sterile soil with a little clay if you can find it. We put 14-14-14 in the soil at repotting time. In May you can place your bougie in a sunny, reasonably protected spot on a balcony or terrace. If there is a frost expected, it is recommended to bring it back indoors. Its water requirements will increase now that its outdoors, especially in sunny weather. There is no need to feed the plant yet.

Remember that it will produce more flowers if kept on the dry side in the Spring. Actually it flowers best under stress. It will need water almost every day in Summer. Make sure that excess water can drain away. Fertilize once a week with a fertilizer such as Powerbloom 10-40-25.

In Autumn, the water requirements will drop again. Guard against overwatering when conditions turn wet and dark. Stop feeding the plant after September to prevent it growing too actively at the beginning of winter. The bougainvillea can withstand night frost of up to 1 or 2 degrees Centigrade. You need to bring it inside when the daytime temperatures are 6-8 degrees Centigrade. Place it in a cool light spot. A temperature between 0 and 12 degrees Centigrade is ideal. It will lose leaves during winter dormancy. This will not damage the recovery of the plant. Water very sparingly during this time, and there is no need to fertilize in the winter. You only need to prune your bougainvillea if you feel it is getting too large. February is the best time for pruning. It may mean less flowers on the pruned branches next summer, although I have found that they flower voraciously no matter what.

June 2010.