I live in Toronto and have what I think are dracaenas (please see picture). I keep them outside during the warm months and take them inside during the winter. They seem to have done well in their containers but I find that they have grown too tall. Is there a way of pruning this plant? Or should I take a cutting and start a new plant?
Hard to tell from your photograph however, it appears that you have a Dracaena marginata,or Madagascar dragon palm.
The Dracaena dragon palm is slow-growing but will reach 1.8m indoors.Dragon palms are apical dominant, which means they use most of their energy to induce growth at the top of the stem. This causes the bottom of the plant to appear bare as it grows.Cutting the stems/canes to the desired height in Spring or early Summer to control its growth will force the plant to sprout multiple side branches within weeks from where it was cut. The top section that was removed can be planted in a mixture of perlite and peat moss, make sure that the pot has adequate drainage. With plenty of water, protection from direct sunlight, proper humidity, the tip will root and new growth will soon begin to sprout.
When the leaf growth becomes excessive it is best to trim away some leaves to help promote vigorous, healthy growth of the remaining leaves. As the plant ages, leaves will naturally turn brown and fall from the plant. Any leaves that develop brown sections should be trimmed, leaving the healthy green parts intact. Trimming browned areas improves the overall look of the plant and stops further damage to the leaves. Dracaena dragon palms that receive regular high humidity grow faster and stronger, but care when watering is essential as over-watering causes the leaves to turn brown; the plant requires watering only when the top layer of the soil begins to feel dry. Fertilize every two weeks in Spring and Summer with a 10-10-10 fertilizer diluted by half will keep your houseplant healthy for years to come.