Wondering how to treat your ailing plants? Gardening expert Mark Cullen is here with the answers to your questions.

1. Dorothy Fieldhouse: I have a palm plant in my living room and it has brown fringes on the ends of the branches. What's ailing it?

Mark's answer: Brown edges can be caused by watering with tap water. Fill the watering can with water and let it sit overnight before watering the palm plant. Another reason for brown edges on a palm plant could be dry air. Mist the air around the plant to increase the humidity level.

2. Joanne Middleton: I have wanted to grow basil and other such herbs indoors for awhile now. Reading advice on the Internet is not helpful as there are too many conflicting ideas. What do I do to get herbs to grow indoors? Any help and/or advice would be greatly appreciated.

Mark's answer: When growing herbs indoors, use a well-drained potting mix and containers with adequate drainage holes. Trim back the plants on a regular basis to encourage new growth. Generally, herbs need five hours of direct light each day. Place them in south- or west-facing windows, as close to the glass as possible.

3. Jane McGhee Smith: How do you keep rabbits from eating all of your plants -- humanely that is!

Mark's answer: I recently started using Bobbex to protect my plants from deer and rabbits. It's all-natural and non-toxic. Spray it on the plants and, once it dries, it does not wash off in the rain.

4. John Dooling: Tomatoes are pretty hard for newbie growers. Any advice for the beginners?

Mark's answer: Try my recipe for tomatoes.

  • 1. Dig a hole the size of a half bushel.
  • 2. Fill the hole with a mix of half compost, half topsoil.
  • 3. Make a crater in the soil and push the young tomato plant into the soil up to the first set of true leaves.
  • 4. Water well and mulch with 5 cm of cedar bark mulch or 15 cm of clean straw.
  • 5. Stake with a metal spiral stake during the second half of June.
  • 6. Spray with Bordo mixture in July to prevent early blight.
  • 7. Harvest often -- do not allow fruit to rot.
  • 8. Rotate tomatoes (and all edible crops) to a new location each year to reduce the occurrence of pest and disease problems.

5. Helen Williams: I have unplanted spring bulbs. Can I store them or are they going to dry out and die?

Mark's answer: It's not a good idea to hold spring bulbs over the winter as they need that cold period to stratify and bloom. You could try potting them up now for later bloom, but you will need to store them in the fridge.

6. Leola Hordijk: Did you mention a website after Wild About Gardening but before Garden Import in regards to garden travel? Thanks!

Mark's answer: Yes. I mentioned www.icangarden.com. This site is run by Donna Dawson who reports on her extensive travels.

7. Brad Boomhour: Why are Peppers so hard for me to grow? I keep trying but I just can't get them to grow.

Mark's answer: Peppers require eight hours of full sun each day and lots of heat. They like warm, loose, well-drained soil. Consistent, generous watering is important for good production.

8. Mandy MacMillan: When starting tomato plants from the seed inside, when is the absolute latest one should plant them?

Mark's answer: Tomatoes seeds should be started 6 to 8 weeks before the last frost date in your area.

9. Amanda Kerr: Is it really better to separate perennials? My Hosta, Daylily and Sedum look so beautiful and full -- I almost hate to do it. All of them seem to be thriving just fine. Most have been in the ground, unseparated for upwards of 7 years.

Mark's answer: Older perennials will often stop flowering. You may notice bare patches in the centre of a clump of Hostas. Dividing these perennials will get them flowering again. Dividing gives you the opportunity to remove dead patches and replant the smaller divisions around the garden.

10. Cindy Bailey: I can never get my Lenten Rose Hellebore to survive outside in Muskoka. It was told to me they are from British Columbia and thrive and bloom through the spring snows.

Mark's answer: Make sure the Hellebores you are growing are hardy to your growing zone. Muskoka is in the hardiness zone 4a. Some of the new Hybrid Hellebores are only hardy to zone 6.

11. Bren Cat: Do you know of anyone who can come out and tell me what is growing in my gardens. Flowers or weeds?

Mark's answer: You can "share" photos on my Facebook page. My followers are always happy to help identify plants, and they are usually faster than me.

12. Gord Reptile: Where do you get tobacco seeds? I want to try to grow some for friends that smoke.

Mark's answer: Richters Herbs sells Delgold Tobacco seeds. Delgold is one of the best known varieties for commercial tobacco production.

13. Lynn Hefler: I had a cherry tree that died last year for no apparent reason we could discover. No blight or bugs, had an amazing fruit harvest the summer past. We had it for three years and the base of the tree was about the size of a pop can, if not a bit larger. It did look as though the roots didn't expand into the hard Nova Scotian clay soil the way I thought it should and was more of a root ball. Also, last winter we had snow right up to the branches (about 4 feet). I planted other cherry and fruit trees around the same time. What can I do to make this the only loss?

Mark's answer: I suspect the tree did not develop an adequate root system. Encourage a more extensive root system by watering outside of the drip line. Topdress with organic compost each spring. Spread the compost from the dripline outward to improve the soil and provide nutrients.

14. Grace Niezen: How dangerous is this mild winter to perennials and trees? My Irises were sprouting in December and some others seem to have started to come up since then. I put heavy covering of leaves down in December after Irises were noticed, but am still concerned. I have also noticed that trees seem about to bud.

Mark's answer: This winter has been difficult in Southern Ontario. We have experienced a number of freeze/thaw cycles. Tender perennials may be slow to recover this spring. However, the wet weather should help trees and evergreens withstand the varying temperatures without desiccation.

15. Michelle Phinney-Keddy: Hi Mark, I saw a segment you did last summer at your home about cutting gardens. Would love to put one in this year. We live on the Atlantic coast in Nova Scotia. Which varieties are best for our locations?

Mark's answer:

  • Annuals: Zinnia, Sunflower, Poppy
  • Perennials: Rudbeckia, Veronica, Lupine, Echinacea, Foxglove, Aster, Yarrow, Heuchera.

16. Brian Simpson: When is the best time to fertilize Rhododendrons in Toronto? And what do we use and how?

Mark's answer: Rhododendrons benefit from an application of acid fertilizer in the spring. Do not over feed and do not fertilizer after June 30.

17. Cindy Daoust: Recently downsized to a townhome. Have to start over with gardens! I'm a good gardener, but not a good designer. Where can I get help with designing a small (but beautiful!) garden?

Mark's answer: If you live in the GTA, I recommend you visit Sheridan Nurseries to consult with their trained designers.

18. Maxine Peebles: I live in South Saskatchewan. Any suggestions for the kind of tomatoes to plant this year? Last year I planted Celebrations -- they didn't do so well. Big Girl and Big Boys produced lots, but had a touch of blight.

Mark's answer: Rotate your tomato crops to a new location this year to reduce the chance of blight. Do not plant your tomatoes outside until the soil is warm. Plant young tomato plants deeply -- up to the first set of leaves. I grow Brandywine and Early Canadian Beef tomatoes. Spray with Bordo Copper in July to prevent blight in August.

19. Carol Dawn Tulk: What indoor plants are poisonous for dogs and cats? I love indoor plants, but hesitate because of my dog and feline family members.

Mark's answer: The ASPCA website has an extensive list of Toxic and Non-Toxic plants.

20. Judy Lloyd: My son gave me a Money Tree last week for my birthday. The lower leaves are turning yellow and falling off. What am I doing wrong? Over watering? I would be very grateful for your help.

Mark's answer: Money Trees require well-drained soil. Make sure the container drains freely from the bottom. Provide indirect, moderate sunlight. Do not place in a bright window. Water a Money Tree once a week. Do not over water.

21. Claire Van Beek Rogers: I used my old leaves to cover my gardens. What do I do with them in the spring?

Mark's answer: Dig the leaves into the garden in the spring. They will decompose and improve the garden soil.