Marianne Binetti

Tomatoes need heat to thrive

Every spring, readers ask me gardening questions. Have one? Send it to me at

Q. When can I plant tomatoes? Do they grow better in pots or in the ground? — J.T., email

A. Tomatoes are warm-season, heat-loving plants, which means they suffer if the nighttime temps are any lower than 45 degrees. That means waiting until June before allowing young tomatoes to suffer outdoors all night in the cold cruel world.

You can cheat and set your plants out in early May if you have a warm and protected area such as up against the sunny side of a building and under the cover of a roof overhang or eaves.

Growing tomatoes in black plastic pots (they absorb heat) gets them off to a better start in our cool summer climate than growing them in the cold ground, but by the end of summer the tomato plants placed directly into the soil may produce a larger harvest as their roots will have more room to spread and grow.

Q. What can I do about all the slugs in my garden? I also have snails, and they eat new seedlings right after they sprout. — R., email

A. Take a three-prong approach to battling slugs and snails and grab a fork while you’re at it. A fork to stab and collect slugs after a rainfall or at night means you can drop them into a bucket of salt or soapy water. You can also stomp on snails as you lift them from your plants while on nocturnal slug hunts.

If you don’t want to go out at night, place a piece of damp cardboard near seedlings and collect the slugs that gather under the cardboard in the morning. Next, use a pet-safe slug bait such as Worry Free or Sluggo that will cause the slugs to stop eating and slither under a rock to die. You won’t see the slimy mess, but you will see the results.

Finally, remove slug and snail habitats if possible. Rock piles and chunks of rotting wood and debris are where slugs and snails like to breed and lay eggs.

Q. I love the dramatic color of black mondo grass and would like to use more of it, but it seems to have a high price tag at area nurseries. Is there a way to plant black mondo grass from seed? D.G., Puyallup

A. Not really. Black mondo grass or Ophiopogon planiscarpus ‘Nigrescens’ is actually a member of the lily family, and it grows from bulb-like roots. This lovely, low growing foliage plant keeps its color all year long and is an excellent specimen plant for adding to container gardens or as a dark accent plant in the landscape. The dirt-cheap secret to having more Black Mondo plants is to divide up mother plants into many offspring in early spring. This week is a good one to perform the surgery.

Either lift the clump from the ground and pull it apart or use a sharp spade to make new sections. If you do not divide black mondo grass it will grow slowly, but once you cut it apart the new clumps fatten up into fine specimens that you can replant in any partly-shaded location.