Ask a Gardener

Questions and Answers

Q:  My husband recently purchased several bags of Preen mulch which also has a weed preventer. Before I put it in my flower beds, I want to be sure that it is safe for bees, butterflies, birds, and my dogs that like to walk in my flower beds. I plant lots of bee, bird, and butterfly-friendly flowers and certainly do not want an herbicide in the mulch to cause damage.  Thank you

A:  Here are 2 answers to your question from our 2 local volunteer experts:

  1. Preen should be kept away from water courses (brooks, ponds, fish, amphibians). It is not toxic to birds, butterflies, etc. when used in amounts listed on the label.
  2. Preen has been shown to have low toxicity to humans and mammals, but high toxicity to aquatic wildlife. It should not be used when heavy rain is forecasted and the chemicals could run off into water supply. It should not directly affect pollinators, but, personally, I wouldn’t choose to use it if I had a dog.

    The most important thing would be to thoroughly read the label and follow the application directions. 

    *Just a note….the volunteer that gave answer #2 advocates organic gardening/farming methods.

    Q:  Is there an organic way to get rid of tomato blight?

     A:  “Blight is a fungus, so the best way to manage it is prevention. Early blight is best prevented by heat treating seeds (a process too detailed to explain here but there are many explanations online), selecting resistant varieties, and pruning the plants heavily to encourage good air flow.  Whenever possible an effort should be made to reduce leaf moisture, especially when watering. The same principles apply to late blight (a completely different disease).  There are several organic sprays approved for use, many of them copper based, but they are only effective when applied regularly before any sign of late blight.  We follow disease trackers out of Cornell and UMass to be able to best track the arrival of the disease and reduce our risk.  This is one reason why it is really great to start your own seedlings or purchase locally grown!”

    Q: How long do seeds last, particularly herb and flowers?

    A: There is no single answer to your question, as every seed type is different, however this table may be helpful to you. Also, there is a more comprehensive vegetable seed viability table at the Ledyard Seed Library at Bill Library. When in doubt, you can do a germination test to determine viability rates for your seeds. Instructions for this can also be found in the Resource Binder at the Ledyard Seed Library.

    Seed Viability Chart 

    How do I know if my seed is viable?

    There are various simple tests for viability. One is to dampen a plain white paper towel and fold it in half, place a few seeds on one half of the towel and fold it in half again over the seeds, enclose it in a zip lock sandwich bag and place it in an environment appropriate to the seed’s germination requirements (light, dark, warm, cool, etc.). After a week or so, check to see if any sprouts have appeared.

    Some seeds, such as peas, can be tested for viability by placing them in a bowl of water. Those that float are sterile (contain no embryo and are therefore lighter); those that sink are likely to be viable.

    Q: What is the best way to control tomato worms?

    A. The best way to control Tomato Hornworm is actually the easiest – do nothing! We have a strong local population of parasitic wasps (Cotesia congregatus) that will lay white eggs that resemble rice on the back of the worms. When the wasps hatch, they consume the worm and their natural population continues to thrive.

    If you can’t wait, I’ve found hand picking them to be the best bet. They can be difficult to spot during the day, but they are very easy to spot using a black light after dark. In the very worst of cases, the pesticide Bt is approved for use on Hornworms and is OMRI approved, but thresholds in our area rarely reach a level warranting spray.

    Q: What are the easiest veggies and fruits to start with in a garden for a total beginner? I’m working on setting up an indoor germination station but that is all I have so far. If you have any beginner tips or tricks I’d love to hear them.

    A. My advice for beginner vegetable gardeners is always plant what you most like to eat! Planting is the easiest part of the whole process: you’ll feel more invested in weeding and harvesting if it is something you’re really looking forward to enjoying.

    Crops with a quick turn-around (a short number of days to harvest) that can be direct-seeded into the garden (planted straight outside into the soil and don’t require special conditions for germination) are another great place to start! Lettuce or salad mix, radishes and green beans are three of the easiest.

    As for fruit- most fruits take a year or more to get established. The exception is day-neutral strawberries – which can be planted in early April and will fruit that following summer. It is important to think carefully about where you are planting perennial crops and invest time in preparing the soil.