By Sharleen Pratt, Master Gardener
Continuing on a similar theme to last week’s blog on Orchids by Master Gardener Cheryl Harrison, I thought I would touch on another family of plants that are tropical and exotic; the Bromeliaceae family. Known as Bromeliads, it is a large family which includes more than 50 genera and at least 2,500 known species which are native mainly from an area stretching from the southern U.S. to Central and South America.
Before COVID, we would do an annual visit to the Sarasota area in Florida. One of my favourite places to visit is the Marie Selby Botanical Gardens. Selby Garden botanists have made hundreds of expeditions into the tropics and subtropics and have contributed to the most diverse living and preserved collection of epiphytes in the world. They have a greenhouse that is beautiful to walk through with very knowledgeable volunteers to answer questions.
Many bromeliads are stiff-leaved, rosette-forming plants with brightly coloured leaves, bracts and flowers. The majority of them are epiphytic, meaning that they grow on the branches of trees without taking nutrients from the tree. They can also be lithophytic which means they reside on rocks, and the remaining are generally terrestrial, meaning that they grow in soil. Bromeliad flowers can last several months, but they generally only bloom once. The mother plant will produce new plantlets, also called ‘pups’. They are incredibly resilient but do not like to be overwatered. Their roots are usually used for balance and not for transferring nutrients. Instead, the leaves take in all of the water and nutrients the plant needs. They never breath out carbon dioxide almost as if they hold their breath in order not to lose moisture. It is a very special photosynthesis.
Many bromeliads have leaves that form a reservoir to hold water at their bases (known as tank bromeliads), with the largest holding up to two gallons of water. Types that don’t hold water are called xerophytic or atmospheric bromeliads.
One of the most well-known Bromeliads is in the Ananas genera. This is the pineapple, Ananas comosus. Europeans first found out about bromeliads when Columbus went on his second trip to the New World in 1493. The pineapple was being cultivated by the Carib tribe in the West Indies. After colonization, it was rapidly transported to all areas of the tropics and became a very important fruit.
Another genus is Tillandsia. It is the largest group in the family and this genus is also known as “air plants”. Most do not form tanks and have grey-green leaves and are densely covered with fuzzy scales that give the plants their characteristic colour. Tillandsia require more humidity than other bromeliads and tend to dehydrate in the dry air of most homes, but can still be grown successfully with more frequent watering.
Spanish Moss falls under this genus, Tillandsia usneoides. It is very prevalent in Florida and is neither Spanish nor a moss. Unlike other epiphytes that have roots to anchor themselves to their host tree, Spanish moss has tiny scales on its leaves and its curved structure to cling to its host tree. It is important for diversity as its large mats that drip from trees harbor a great variety of insects, birds and bats. In Florida, you usually see Spanish Moss clinging to Live Oaks.
Bromeliads will survive for months or even years under less than ideal conditions. They need satisfactory light, temperature and humidity. It is best to use water that is not softened. You should use a potting mix that holds moisture yet drains quickly. Orchid bark mixed with course perlite and humus is good for most bromeliads. The small air plants only need to be misted with a spray bottle or put in a bowl of water for an hour. If you would like to learn more about these amazing plants, visit University of Wisconsin-Madison.