ARTICLES from GROWSEARCH

 An office from hell?

The ‘sick building’ syndrome is alive and well … Energy-efficient, sealed office blocks, are often 10 times more polluted than the air outside.  Recent studies show that 40% of absenteeism in the US can be attributed to indoor air quality-related issues.  Plants certainly make a difference in reducing air pollution.  Recent research shows that plant-filled rooms contain 50-60 percent fewer disease-causing airborne moulds and bacteria than rooms without plants.  Jay Naar, author of Design for a Liveable Planet, suggests 15-20 plants are enough to clean the air in a 1,500 square foot area. From www.jcaho.org

Boost productivity and keep your cool

Recent studies have shown that interior plants (especially philodendrons) enhance office productivity by 12 percent.  If the indoor plant is a tree, you could also save up to 20 percent on cooling costs.  During summer months, one large tree can absorb as much heat as several window air conditioners and can lower temperatures by 10 degrees. From Buildings Sept 2002

 People and Plants meet at Opryland

With over 18,000 indoor plants, the Opryland Hotel in Nashville, Tennessee must be the ultimate indoor plantscape.  There are two six-storey semi-tropical indoor gardens featuring fountains, waterfalls, over 600 plant species, and a 2-acre conservatory.  The hotel owners believe the plants help to keep their occupancy rate up in the 85% bracket and allow them to raise prices considerably for rooms with garden views. From "People and plants: a case study in the hotel industry" Timber Press, Portland, Oregon.

New white caladium in 2003

Researchers from the University of Florida have developed a new caladium, “Florida Moonlight”, which is suitable for small containers.  The new variety will be commercially available in early 2003.  It has large, heart-shaped, white leaves edged with a thin green margin and with a bright purple streak in the centre.From GMPRO July 2002

What are US interior landscapers talking about? 

Hot trend in the USA Lucky bamboo, trendy throughout Europe, has surged in popularity over the last 12 months in the US. Retailers like it because it's a novelty, an easy care plant with a long shelf life and a good profit item. Lucky bamboo is not actually related to the Bambusa family it is a Dracaena. Various Asian countries are now exporting the plant into the United States. It is usually shipped in a nonpolymer gel, which keeps the plant alive for up to two months without water. From Produce Business March 2002

A new one for Valentine's Day? A heart-shaped hoya (Hoya kerrii) has been voted the most promising indoor plant innovation at the spring plant fair at Naaldwijk in the Netherlands. The plant with large, glossy heart-shaped leaves grows to about 20cm tall and is expected to sell as a gift item for special occasions. From Grower March 2002

A strange combination? Siamese fighting fish and the peace lily must be the ultimate "odd couple" to appear in interiors throughout the US. To assemble this combination of indoor plant/aquarium, you need a fairly large glass vase, some pebbles, a spathiphyllum with washed and trimmed roots, de-chlorinated water and one of those interesting Betta splendens fighting fish (they fight to the death in a mixed aquarium). You need to provide regular fish food, change the water regularly and don't put in any more fish! From Horticulture Magazine 2002

Atrium psychology! We've heard about how plants can relieve the "sick building" syndrome. Now researchers have investigated the "well being" aspect of interior plants when added to atriums in public buildings. Public perceptions of the plant-filled atriums were: *Relaxed and welcoming *Expensive-looking *Less noisy *Colourful *Less stressful *Cheerful People positioned themselves opposite plants in waiting room or snack bar areas. In fact, there were no negative findings for the "with plants" buildings. From www.interiorscape.com

Seawater greenhouse? A British company has developed a self-regulating greenhouse suitable for the hot, arid, coastal regions of the world. The Seawater greenhouse consists of a light metal structure supporting an outer sheet of clear polyethylene and a partial second roof, coated to modify light and heat by reflecting ultraviolet light and absorbing infrared light. This keeps the greenhouse cool and permits the penetration of photosynthetically active light. A fan draws hot air from outside through an evaporator on one of the outside walls. Seawater is pumped to the top of the evaporator and trickles through the coated mesh surface. In the process, the air is cooled, humidified and drawn into the greenhouse. Hot, dry air is collected from between the two roof layers and pushed towards a second evaporator. When the hot, dry air meets the cooler, humid air inside the greenhouse it absorbs moisture and pure water is condensed out of the air when it touches the cold surface of an aluminium condenser. Cold, deep seawater is pumped through the condensers to keep them cool. The pure water is collected for irrigation water and the seawater that emerges from the condensers is pumped back into the ocean. Solar power is used to power the pumps and fans. From GrowerTalks Nov 2002

"Water plants" with a difference. A fast rising trend in the US is to grow water plants indoors, not in a fishy aquarium situation but on their own in any clear container. They can fit onto a window-ledge or desktop and require no maintenance other than a regular change of water. A Dutch grower packages them six per box, each in its own small clay pot to add weight to the base. From Green Profit Feb 2003

A new biodegradable potato pot. It's not for growing potatoes in - it's made from potato peels. It has the look and feel of plastic and can be coloured with food dyes. The pots last from four to eight months after which time they can be discarded in the compost heap. They will degrade within about two months. A Netherlands company will introduce the pots into the US after a launch in Europe. From Green Profit Feb 2003

How to turn a $2 item into a $7 gift! The answer is in colour coordination. At the recent Hortifair in Holland, a European company, Zwapak, turned a simple African violet into a striking gift by the addition of just 50 cents in add-ons (a lime green pot and artistic packaging). Also at the fair, a Danish company, Jackpot, introduced a line of silver and gold-frosted pots for Christmas holiday sales. From Green Profit Feb 2003

New ivy for full sun and full shade. Hedera helix 'Golden Ingot' has been chosen as Ivy of the Year 2003 by the American Ivy Society. This variegated ivy, originally from Denmark, has bright-yellow leaves edged with dark green with centers of vibrant green and grey. It can be grown outdoors in full sun to almost full shade. From GMPRO Dec 2002

Pest defences against biological controls. When using biological control agents it is important to release them early enough before insect pests implement some of their defense mechanisms. Mealybugs and scales will clump in groups one on top of the other so that the eggs and individuals on the bottom of the pile escape attack. Twospotted mites produce webbing that catches predators. The predators tire themselves getting free, then clean themselves thoroughly (time better spent catching the mites). Western flower thrips hide, fungus gnats tunnel into cuttings, and some insects produce an unpleasant, wet, anal exudate that covers predatory mites. The more liquid parasitoids are covered with, the longer they spend cleaning themselves. From GMPRO Nov 2002

Dual purpose plants

 Researchers from Michigan State University have conducted experiments on selected perennials that can be grown as indoor flowering plants and then moved outside and planted in the garden. The most versatile plants included: Lavandula angustifolia (good in the interior and great in the garden); Pennisetum setaceum (great potential - intense foliage colour under low light and an absolute winner in the garden); Geranium dalmaticum (great potenial as a flowering pot plant and good in the garden); Aquilegia flabellata (great potential as a container plant and good in the garden). From GMPRO Jan 2002

A new way to treat thrips 

Researchers at Cornell University have proposed a novel method of beating greenhouse thrips by completely eliminating the pests before spring production starts. The following steps are suggested:

1. Remove all plant material from the greenhouse.
2. Eliminate weeds that serve as host plants for thrips and tospoviruses. 
3. Heat the greenhouse until soil temperatures reach 60F (15°C) and maintain for 3 weeks. 

The warm soil temperatures promote thrips emergence from the pupal stage in about two weeks. Without plants, the thrips starve within a week. 4. To make sure all thrips are killed, apply smoke or aerosol insecticides after the second week. From Growertalks Feb 2002

A Miami nursery has a new way to display and sell small foliage plants - in natural snail shells. Plants with low water requirements, such as bromeliads and trailing or climbing plants like Dischidia pectinoides, are ideal for the aquatic snail shells which are displayed as miniature hanging baskets. From GMPRO Dec 2001

Colour trends for 2003 

The Color Marketing Group in the US predicts that blue will be the dominant colour for plants in '03, with pinks and browns "highly visible". The Group expects the trendy colours for garden accessories will include: *Currant (brown and violet) *Pinkle (velvety pink) *Sweetheart (cooler vintage red) *Lion king (regal gold) *Champagne bubble (silver & gold) Consumers most likely to coordinate colours are only 18% of the gardening public, but they spend 25% of the gardening dollars. Their primary motivation for buying plants is to enhance the beauty of their homes. From GMPRO Nov 2002

Tea bags for plants

 Nutricote®, the slow release fertilizer, is now available in 'tea bag' form. The 'bags' are designed for pots, baskets and tubs and are formulated to give a quick boost or to release fertilizer on a long term basis for planters. From Grower July 2002

Another weapon in the whitefly battle.

 Researchers at the University of California have found that whiteflies are attracted to UV light. Tests on greenhouses with and without UV-blocking plastics and screens showed that 85 to 94% of the whiteflies went toward the standard plastic rather than the UV-blocking one. The researchers haven't found any evidence of undesirable effects on plant colour or growth with the UV-blocking films, but caution that the technique doesn't work on open-sided greenhouses. From GrowerTalks June 2000

The ZZ plant is hot in Florida.

 Zamioculcus zamiifolia may be a bit of a mouthful but the foliage plant is all the rage in Florida homes this year. The rigid, palm-like foliage grows quickly. It suits low-light, indoor situations and thrives even in the most neglectful conditions. From GrowerTalks July 2002

Smoko for snails?

 Scientists from the United States Agricultural Research Service have found that the application of a 2% caffeine spray to coir-based potting media kills 95% of pest snails on orchids. The researchers believe that the caffeine penetrates the snails' mucus, then acts on the nervous system making the dying snails writhe uncontrollably. (Thinking of giving up coffee again?). From Grower July 2002