Many listeners have written to ask why there's been no GardenLine tip for the past two weeks. Essentially, I took a two-week hiatus because of a death in the family and for spring break with my kids. But we're back, and the tips will be consistently issued now through the end of the year. Thanks for your patience and understanding.

Houseplants

This update of a previous tip sheet has been a long time coming. It's a great compilation of all the things I think make house plants and indoor tropicals easy. 

If you could look into my virtual garage (my brain), you'd see that there's not only a lot of gardening material up there, there are way too many "soapboxes" ... gardening issues that I get all lathered up about. The list includes the pathetic job some "landscapers" do on new-construction homes. Another is people who still bag grass clippings instead of mulch mowing. And there are the annual "Crape Myrtle Massacre" and the heinous use of atrazine-based weed-and-feeds. But possibly my biggest soap box issue is the trend toward plastic indoor plants. 

First, don't tell me you have a "brown thumb." That's the worst excuse for not growing live tropical plants inside. If I can grow indoor plants successfully, anyone can. I'll admit it was touch-and-go for a while after the birth of our son in 2001. With his curiosity and urge to put everything his mouth, most of my indoor plants were banished to the back porch where they suffered. But I kept 'em alive, and eventually they all found their way back indoors. 

You too can grow indoor plants with the five points below. Your brown thumb could turn green in a matter of weeks. And as my British friend, Martin (not the tree guy Martin), would say, they're "right proper."

  1. Proper soil
  2. Proper drainage and moisture retention
  3. Proper lighting
  4. Occasional feedings (not very proper, I admit)
  5. Proper plant selection


PROPER SOIL

First, it doesn't matter whether you buy a plant yourself, are willed it by someone moving away, or if you get one as a gift, you should immediately change the potting soil. The soil that plants come in is usually too light and fluffy. It needs to be that way at the floral shop or nursery because they usually water their plants every single day. You won't. So don't buy the fluffy stuff you find on the shelves at mass-merchandisers. It's too light and drains too fast. 

The best potting soil is fluffier than outdoor bedding soil, but it has some actual soil in it. Also some sand or perlite. Those soils hold on to the moisture for longer than a day. But you should also avoid heavy peat moss-based soils. If peat is among the top three ingredients listed on the label, avoid it. My favorites are Vortex Potting Soil, Jungle Land Water Saver and Potting Mix from The Ground Up, potting soils from Nature's Way, and Organic Soil Complete from The Arbor Gate. I also think bags marked "organic potting soil," or "humus soil" work fine as long as they're not heavy on peat.

PROPER DRAINAGE AND MOISTURE

Over watering and under watering are probably the two biggest destroyers of house plants. With the right kind of potting soil, you're already headed in the right direction for moisture retention. But unless you totally ignore your plants and they dry out and die, over watering usually brings about the most common death sentence. Excess water combines with improper drainage and forces the roots of the plant to continually rest in water. Essentially, they drown and die of root rot. But if you follow my advice and avoid peat-based soils, you won't likely have that problem. 

So, how much water should you give your plants? It would be simple to say once a week. But it's not that simple. Light factors, temperature, humidity, the container and, of course, the type of plant all combine to set the water requirements of each plant. Still, there's no need for gadgets to read soil moisture — it simply comes down to using your eyes and your fingers. 

Assuming you use the right soil and have proper drainage, if your plant is drooping or wilting it probably needs a drink of water. But the sight method alone doesn't always work. So the most tried-and-true method of judging a plant's water needs is the finger test. Simply poke a finger an inch or so into the soil. If it feels dry, add some water. If the soil is still moist, it doesn't need water. You should test them once every week to two weeks when you first take ownership. Yes, I realize that is arduous. But once you figure out a schedule, it just becomes part of your routine. 

If you're like me, you'll water some plants every other week and some once a week ... some just dry out quicker than others. Remember to give each plant a thorough soaking. If you only water the top couple of inches, the roots will never receive an adequate amount. 

As for drainage, you must create some space at the bottom of the plant's container. TV horticulturists and authors of gardening books sing the praises of broken pieces terra cotta clay pots at the bottom. It's an excellent idea. But what if you don't have any? You can use broken pieces of brick. I've successfully used pea gravel and river rock. I've seen others use broken twigs and large pieces of pine bark nuggets. Any of these items placed at the bottom of every container will result in proper drainage. Also, don't forget drainage holes. Most containers have them, but if yours don't, you'll need to create two to three on their bottoms. 

PROPER LIGHT

This is simple. Most house plants grow best in areas with "indirect light." That means they need lots of light, but not direct sunlight. Think about the atriums of many office buildings. They usually have opaque roofs that let in plenty of light, but no direct sunshine. If you get early morning sun from east-facing windows, that's usually okay for tropicals and house plants. However, west-entering sun is usually deadly. If you can't provide consistent, indirect light, then lots of fluorescent lighting will often work. 

OCCASIONAL FEEDINGS

Also fairly simple. The key word is "occasional." Most house plants just need a twice-a-year feeding. I'm not kidding. They make slow-release granules, house plant spikes and, of course, the ever-popular water-soluble fertilizers. And as long as you stay away from "bloom booster" type fertilizers, almost anything will work. My personal choice is Lady Bug Natural's Mama's Home Brew and organic 6-3-6. I've also had lots of success with Medina Hasta Gro, a 6-12-6 organically derived all-purpose fertilizer. And to green up some yellowing indoor plants, use fish emulsion. If you can handle the smell, take the plants outdoors once a year, feed them with it, and you'll see an intense greening up.

PROPER PLANT SELECTION

I'll just give you my list. If you follow the rules above with any of these plants, you will succeed. 

  • Arrowhead
  • Asparagus Fern 
  • Bromeliads
  • China Doll 
  • Chinese Evergreens (Aglaonema) 
  • Diffenbachia (Dumb Cane) 
  • Dracaena (corn plants) 
  • Ficus Tree (Ficus Benjamina) 
  • Parlor Palm (Kentia palm) 
  • Philodendron 
  • Pothos Ivy 
  • Rubber Tree Plant (Ficus elastic) 
  • Snake Plant (Mother-in-law tongue) 
  • Spathiphyllum (Peace lily) 
  • Spider Plant (Airplane plant) 
  • Tolmiea (Mother of Thousands)