Guest Author - Susan MacNeil

This is the 4th and final article on growing miniature roses indoors. It will cover humidity, temperature, and ventilation requirements. Once you’ve read this you will have a complete overview of the most important elements needed to successfully grow miniature roses inside. I welcome any comments or questions you may have!

HUMIDITY: Miniature roses grown indoors need a lot of humidity. Moisture is needed to maintain a healthy environment and prevent certain problems such as spider mites. A level 50-55% humidity is recommended.

This is especially important in the wintertime, when central heating dries out the air in most homes and drops the humidity level down to as low as 15 to 20%.
This can be compensated for by running a humidifier or cool mist vaporizer. (You’ll probably appreciate it as much as your plants as such low humidity can lead to dry skin and scratchy throats!)

Another way to raise humidity is to place your rose plants on trays filled with water and pebbles, pea gravel, river rock, aquarium gravel, or any small non-absorbent object or by placing containers filled with water between the pots. As the water evaporates, it will give the plants the extra humidity that they need. It is a good idea to cover the gravel using hardware cloth for the plants to sit on. Keep water filled to two thirds of the way to the top of the gravel to keep the humidity stable. Do not let the plants sit directly on the gravel unless you are sure they are not in contact with the water. You don’t want them to have wet feet as that can lead to fungal problems and root rot.

You can also help boost humidity levels by grouping your plants together. Plants naturally give off moisture as they “breathe” and by placing them in groups they naturally raise the humidity of the air around them. Just remember to make sure proper air circulation is maintained.

Misting the plants once or twice to helps to maintain humidity. Humidity that is too low can cause leaves to curl, buds to dry out and drop and leaves to turn yellow. Make sure the water you use is room temperature and has been allowed to sit for a few hours to allow any gases(such as chlorine) to dissipate.

TEMPERATURE: Indoor temperature is extremely important to rose growth. Normal room temps of 65 to 75 F are fine, but the night temps should be in the 60’s while the day temps should be in the mid 70’s. The warmer days help the plant make food and the cooler nights help them use it. Keep away from drafts at all times.

VENTILATION AND AIR FLOW: Ventilation is the circulation of fresh air. All roses, including indoor roses need air flow and ventilation. Place a small fan that sweeps back and forth on low and this will provide the necessary airflow. You can run it 24 hours a day to make sure that there is constant air movement. Mildew attacks increase with still air. The leaves of plants constantly release moisture so air movement is necessary to keep it from condensing on the leaves. Ventilation is also necessary to supply carbon dioxide to the plant. The leaves take in carbon dioxide when there is light, and release oxygen when it is dark.

I hope this series has been helpful to you! Feel free to drop by our forum and discuss it and roses in general.