How to Grow Long Stem Roses in a Greenhouse

Long stem roses are the classic gift rose. Whether the bouquet consists of a dozen red ones or a single, perfect yellow bloom, their slender, tall stems and large flowers make them the most romantic kind of rose. The easiest and most efficient way to grow your own long stem roses is in a greenhouse. You won't have to worry about the fluctuations of the weather outside, and you can spend your valuable time smelling the roses instead of worrying about the upcoming thunderstorm.

Things You'll Need

• Pruning shears
• Rose fertilizer
• Carbon dioxide generator

Instructions

1. Keep the temperature of your greenhouse constant.The ideal temperature for long stem roses is 70 degrees F (21 degrees Celsius), but once the rosebuds have reached the size of a pea, you can lower the temperature to about 61 degrees F (16 degrees Celsius) during the nighttime. A consistent temperature will give your roses a longer life once they're cut.

2. Keep the humidity around 60 percent, but lower it a bit during the night to no less than 40 percent. Too much moisture will create sickness and rot in the greenhouse. Too little moisture will stunt the plants. A constant humidity level is very important for the growth of long stems and big flowers.

3. 

   Prune all of the side buds off your rose stems, leaving only the biggest bud on top of the stem. This will create a single, big blossom on top of a long stem. Remove all dead blossoms regularly, and prune the old branches from the center of the rose bush.

4. Use fertilizer designed for roses---about 3 lbs. for every 100 square feet. Don't fertilize during planting, though, as you may burn the rose bush.

5. Water your roses in the morning, so they have a chance to absorb the water throughout the day. This will discourage the growth of fungi. Long stem roses need about 1 to 3 inches of water a week, but make sure that your soil is well-drained so that sitting water doesn't rot the roots.

6. Adding extra carbon dioxide to the air, known as carbon dioxide supplementation, is a popular method among greenhouse growers. Carbon dioxide is essential for photosynthesis, and supplementation can result in quicker flowering, more roses per bush, and and bigger blooms. Carbon dioxide generators burn natural gas, propane or other liquid fuels to release CO2 into the air of the greenhouse. Make sure the generator burns the fuel completely.

Resources

• Heirloom Roses