Question: I bought seeds on sale last fall and I didn't store them carefully. How can I tell if they are still viable?
Answer: Here's a fairly quick way to test the viability of your old seeds:
Dampen a thick paper towel. Sprinkle some seeds on the paper towel (you don't have to use all the seeds). Gently roll up the towel and store in a sealable plastic bag. Place the bag in a warm area (about 75°F; the top of a refrigerator works well) and keep away from direct sun. Check the seed packet for number of days to germination, and start checking your seeds a few days before the recommended number. Once germinated, you can transfer the seeds in to a soil medium. You can determine the rate of germination by counting germinated seeds (e.g., if 10 seeds out of 100 germinate you can estimate that 10 percent of the seeds in the packet are viable).
Question: I stop feeding my houseplants during the winter. When should I start feeding them again?
Answer: Watch the plant, typically it will show you! Once you see new growth (around mid-February when days grow longer) start feeding, but don't get carried away. More is not better. I advise feeding at 50 percent strength of recommended applications. Also, different plants need different nutrients, so make sure your feeding program is appropriate for your plants. When in doubt, you can't go wrong with an all-purpose houseplant fertilizer. I prefer using organic plant food, which is widely available at garden centers and nurseries. And be careful with the watering. People are more likely to kill plants by over-watering them. Water only when the top inch of soil begins to dry out. Remember that water requirements also vary from one plant to the next.