Why Use Isolation Techniques for Saving Seed?
- Goal – produce true to type seeds
- Prevent unwanted cross pollination by isolation
- Seeds are collected from a number of plants of the same variety, protecting the variety’s genetic diversity (prevents the loss of a variety’s unique characteristics – i.e. form, color and taste)
- Seeds collected from a number of plants of the same variety, is essential to the health and performance of the variety.
- Seeds collected in your garden are unique to the changing conditions of your area.
- These seeds are now a one of kind variety for your special use.
- Isolation – the use of spatial distance or physical barriers to prevent pollination by wind, vibration, insects or mechanical means.
- Isolation techniques:
- Blossom bagging – netting material that is a physical barrier to insects that are drawn to the flowers of vegetables, herbs and flowers that you intend for seed saving.
- Blossom bags are used around individual (okra) or clusters (tomatoes) of flowers.
- Blossom bags (made of very fine screening) may be purchased through online horticultural supply distributors and high end garden centers.
- Caging – a physical barrier made of a frame and screen/row cover to prevent cross pollination of insect pollinated plants.
- Self pollinated vegetables suitable for caging include eggplant, pepper and tomato.
- Floating Row Cover material/very fine screening may be purchased online from horticultural suppliers or high end garden centers.
- Bagging and caging are useful for those who have limited space and/or cannot meet distance requirements.
- The netting or row cover material will prevent inadvertent cross pollination by wind or vibration.
Here are two excellent publications for more in-depth information regarding seed saving!
Please contact me for any question or observation you have regarding seed saving!
I just uploaded a new video documenting how to make and install floating row covers.
Supplies you will need:
- Rebar – 3/8″ x 10′, cut into 5 – 2′ lengths
- Electrical PVC – 1/2″ diameter pipe x 9′
- Floating Row Cover fabric
- Angle Cutter or equivalent for cutting lengths of rebar
- Hack Saw or PVC Pipe Cutter
- Gloves and Safety Glasses
Low tunnels using floating row covers is of great benefit for several reasons.
- Floating row cover is a light weight, breathable fabric that allows air, moisture and sunlight to pass through the material.
- There are various fabric weights to meet different needs.
- Agribon 15 is lightweight fabric that is used for insect protection and shading.
- Agribon 50 is a heavy cloth used for freeze and frost protection. This cloth will protect a crop down to 26° (F)
- Insect protection – when properly sealed, insects cannot penetrate the covering which protects the crop from damage and disease.
- Problem insects such as Japanese beetle, squash bugs, squash vine borer, cucumber beetles and flea beetles are blocked from doing their usual mayhem.
- Isolation chambers – Low tunnels are ideal for seed saving of crops such as squash, pumpkin, melons and watermelons. Bumble bee hives may be inserted at one end of the enclosure to insure proper pollination. Plus, there is not a chance of cross pollination. You may grow several varieties side by side. That is a huge advantage.
- Season extension – row covers placed over a crop will allow for early planting by trapping 2° – 8° (F) higher temperature. Likewise using a row cover late in the season will protect the crop from early frost. By using this method you can easily extend your growing season by one month!!!!
- Hoop houses, high tunnels and greenhouses – row cover gives added protection and benefits the grower with lower fuel costs. The insulatory value of the row cover will block some of radiant cold that may damage a crop.
This is another method and tool for your gardening arsenal!!!
You’ve started your summer squash and zucchini. The plants look great! A couple of weeks later, the plants start to wilt and some die. What did I do wrong? After careful observation, you notice there is something that looks like wet sawdust at the base of the plant. Plus, you see small holes in the bottom stem. What is going on?
Your enemy is the Squash Vine Borer!! (SVB)
The female Squash Vine Borer moth (Melitta curcurbitae) lay brown eggs especially on the stems, just above the soil line.
Eggs hatch in 10 days. Once the eggs hatch, they immediately enter the stem, leaving a small hole at the place of entry surrounded by frass (moist sawdust like debris). The larvae (white caterpillars with brown heads) bore into the stem and remain until maturity before pupation (the transformation of the larvae to a pupa(in a cocoon)). They will now stay in the soil (usually 1″-2″) and over winter .
Squash Vine Borer moths emerge from the ground from early spring through mid-summer. The moth looks like a wasp and is a half inch long. The wings are clear and look like a windowpane. Unlike other moths, this one flies during the day and makes a buzzing sound.
Now that you have identified the enemy, what are your weapons of warfare?
- A preemptive strategy would be to use a floating row cover (sheer, light weight fabric that is placed over a crop to protect from insects). It is secured in place to prevent insects from damaging the crop. The row cover is put on at the time of planting until the plants begin to flower. Squash crops require insect pollination.
- Monitor by using a yellow colored bucket trap with water, placed near the newly planted squash plants. The yellow color attracts the moths. Traps must be checked daily. Once you’ve found moths in the traps, start looking for stem damage. This indicates the female moth is out laying eggs.
- Create a barrier on the lower stem by using materials such as aluminum foil. Wrap the foil around the lower stem to confuse and prevent the moth from laying eggs.
- Plant a trap crop of early planted Hubbard squash three (3) weeks prior to planting your preferred squash crop.
- Use succession planting (weather permitting). Have fresh transplants ready to go. A late crop planted after SVB pressure may offer a harvest. Do not plant your late crop where there has been previous pressure from the SVB. Rotate your planting to an unaffected area.
- SVB resistant varieties of squash, such as Waltham Butternut, offer a solid stemmed variety to thwart the penetration of the larvae. Cucurbita moschata are their least favorite, as they are solid stemmed. Cucurbita pepo are their most favorite, as they are hollow stemmed. Seed catalogs will list this information for each squash seed offered.
- When a squash plant has been attacked by the squash vine borer, find the borer by looking for the frass or small holes with frass. Carefully slit open the stem and remove the caterpillar. Cover the wound with fresh soil or compost to encourage the re-rooting of the plant.
- Remove and destroy any plants that are severely wilted or dead immediately. Do not compost these plants!!
- Sanitation is key! Immediately remove your squash vines after harvest. Do not compost!! Burn the vines or bag the vines and remove them from your property. The soil must be exposed to reveal the cocoons.
- Till or fluff the soil up to 2″ to expose SVB cocoons. Songbirds and poultry delight in eating the pupae (cocoons).
- Always rotate your squash crop to another space each year.
My strategy this year includes the Blue Hubbard trap crop and yellow trap buckets. Plus, I will preemptively spray the ground stems with a mixture of vegetable oil and Dipel (Bacillus thuringiensis). I’ll keep you updated throughout the summer.
– Snails! I really REALLY make every effort to garden organically, but I am having an infestation of snails, and am stumped as to what to do about it.
There are many natural solutions for slugs and snails.
- Sanitation is key! Make sure there is no debris for them to hide. Do not plant next to a compost pile.
- Plant trap crops for them to eat. Marigolds, brassicas, melons, lettuce,strawberries, etc. are great attractants of slugs and snails.
- Plant resistant plant varieties – lavender, rosemary, sage, wormwood, impatiens, poppies, geraniums, etc.
- Barriers – copper strips, Diatomaceous Earth, sand, and wood ashes. Be careful with wood ashes! You could make your soil pH go sky high!
- Traps – stale beer in containers at ground level, melon halves turned upside down, untreated wood boards laid on top of the ground.
- Guinea fowl will eat them. They shouldn’t eat your crops!
- Encourage your Lightning Bugs – their larvae eat slugs and snails!!!
- Iron phosphate baits such as Sluggo® or Escar-Go®
That’s quite an arsenal!