Passion Flowers

Q. I have recently purchased a passion flower vine ready to flower. I am in zone 4 we are averaging 50-60 at night and 70-80 daytime. Is it OK to put this plant outside? I am aware that I will have to bring it in in the fall.

A. Yes this plant [Passiflora] is not tolerant of cold as you know. But they do well outdoors for the late spring and summer and then return to the confines of the house for the long winter.

50§F is the minimum I would like to see you subject the plant to. If you could please take the plant outdoors after the sun warms the day let acclimate to the weather and then bring back into the house before temps fall again. Do this for a week and the plant will become hardened as we say.

Once the low temps are above 50§F you may leave the plant outdoors in a very sunny location as long as you watch the watering and keep the soil evenly moist but not soggy. Supply a trellis for climbing and the foliage will receive more light and induce more flowers all summer long. They are a sight to behold when in full bloom with colors ranging from purple-red to lavender to deep rose to pink.

Q. I have a passion flower. Is it best to nip the top out? It is over 7 feet tall which I have grown from seed this year. It is just starting to shot from the main stem.

A. All vines need a little help from time to time. I wish you had pinched out the top growing tip when the vine was about two feet tall. By now you would have many branches going various directions. This increases the spreading of foliage for light and air and thus produces more flowers!

So cut off at least one inch of the growing points wherever they are. That will ensure that the growth cannot continue in a straight line anymore. You will get 2-6 branches coming out below the cut from viable buds all along the main stem. Train each of them with string carefully to stretch over a wall trellis or mesh screen. It will soon be very beautiful.

Congrats for starting your large plant from a little seed. Good for you!

Q. I need information about passion flower plant.

A. This is a wonderful group of plants which are grown worldwide. With a little guidance you will soon be growing some real beauties.

Put your plants close to a wall or fence if possible in beds that are south facing dry and well-drained. Add sharp sand if necessary to improve drainage and help plants establish roots. All Passiflora hate having wet cold roots. Train them up a diamond shaped wooden trellis or similar. Generally all Passiflora love sun.

Very large plants may need little feeding if they have a large root system and are in fertile soil. Smaller ones will benefit from a high potassium fertilizer such as MirAcid or Peters 5-50-5. Organic alternatives include Maxicrop Organic Seaweed Extract banana skins or comfrey. Too much nitrogen gives good leaf growth but few flowers. A stressed plant will flower better than one that is too comfortable.

Water daily when newly planted in the ground. Once established water heavily only once a week to encourage roots to go deep which will increase winter survival chances. Check pot plants every day in summer. If in doubt keep them slightly dry.

Young ones always find their first winter hard. Some plants can regrow from the roots. The more vulnerable plants should be grown in 10" pots with a bamboo tripod and brought indoors at the beginning of winter and kept fairly dry with the emphasis on both good light and air circulation rather than on heating the air. Artificial lighting is very helpful. If you think you might lose a plant in a bed outside over winter take cuttings in the summer to grow indoors over winter.

If getting too big you can cut back in the middle of the growing season but never near the end as the chances of winter survival will be reduced. It is best to leave the plant looking messy over winter and prune only after growth has restarted. Even then never cut the whole plant hard back. Always leave some long straggly bits. When pruning never cut hard to the main stems. Always leave a 3''- 4'' stub.

When they are happy and all their needs are being met they rarely have pest and disease problems. When struggling though especially over winter.