Saturday, May 31, 2014

Cabbageworms are Camping at the Cahill's

Yep, got 'em, the little light green cabbageworms (pieris rapae) on the undersides of my broccoli plants.  These guys aren't really worms, they are the larvae of butterflies who feed on cole crops - including cabbage, broccoli, Brussels sprouts, collards, kale, mustard greens, cauliflower, radish and turnips. There are usually three generations of outbreaks each growing season. 
Cabbageworm gaping leaf damage!
Here's the cycle...the mamma butterfly, whitish with feint black spots (up to four) flits easily around the early spring garden and yard looking for a landing pad for her eggs. Many people are happy to see these early spring butterflies, not me.  I know how quick they are to lay their eggs on any host plant in the area. They deposit an egg on a leaf faster than you can swat a fly, it's a drop and go routine. The eggs are yellow and bullet-shaped and hatch in 3-5 days. They immediately start feeding on the leaf where mamma put them. Notice the small chew holes which will get bigger and bigger over time (days) to the point where you'll see a huge gaping piece of leaf missing (leaf above). Later they'll tunnel into the head of the crops and do more damage.
There he is munching away, leaving holes

Scout your plants often and check under the hood - the under sides of the leaves, this is where you'll find the trouble.  Squish the eggs if you're a good scout (have your hand lens with you or your readers close by). If they are already middle schoolers (green larvae stage), then pick off and squish at this size. Some gardeners dust their cole crops with while flour (under sides too) so that the larvae eat the flour while eating the leaf, then bloat too much and die with a very full stomach.  Red cabbage seems to be less susceptible than green, but both broccoli and cabbage are their favorite cole crops.

They have several natural predators including ground beetles, paper wasps, spiders and parastic wasps. They drown easily from heavy rains or overhead watering.  Use chemical controls as a last resort, try Bt (Bacillus thuringiensis) first, more

Close Up


Monday, May 26, 2014

Plant Root Rights and Wrongs

Despite the recent weather events, you have plants needing to go in the ground, some have been waiting a few weeks (probably the ones you purchased over Mother's Day weekend).  And until the ground dries out you'll probably wait a few more days. Hopefully you acclimated them to the outdoors out of direct contact with the pounding rain or hail (see previous post for hardening off information). This is where shade cloth and floating row covers really come in handy to protect new plantings or existing areas of your garden that you're babysitting until well established.

Root Bound 'Mini-Man' Viburnum (new plant from Fort Collins Wholesale Nursery)

So, you have your planting hole dug to the correct depth, not too deep so it drowns, just a little high is best, especially if you think it will settle a bit. I usually mix in a small amount of slow release fertilizer and a handful or two of finished compost (homemade is best if you have it on hand).  Don't mix too much of non-native soil, otherwise the plant roots won't want to leave the area. Scratch or loosen the sides of the planting hole so the roots don't hit a brick wall as they grow. The planting hole should be two to three times the width of the root ball for the roots to establish. The planting depth is usually the same depth as it was in the container. Trees are the exception (that's a whole other discussion about root flare and planting at the correct depth). 

But what if the roots are compacted in the container?

You can see from the photos that this viburnum is well established in the growing pot, not a deal breaker what so ever, this is what they do, how they grow in a small environment like a container. Often you'll see this in the garden center with annuals and other plants, even to the point where roots are coming out of the bottom of the container, again, no worries.

What to do. It's easy, you want to break up the circled roots so they will reach out into the soil and not continue playing ring around the root ball in the planting hole. Use scissors for larger plants (one gallon or larger), a knife or hori hori  The side of the plant tag is usually strong even to score the sides of smaller 2-3 inch size containers. 

In my example I used scissors and made cuts on four sides and the bottom.  Done, it's that simple. I made sure the new guy has a drip emitter going to the root area, then filled in around with my native soil and some compost.  If it's a really large plant or tree I would fill in soil gradually, then water in between soil layers, this ensures that the root ball gets completely watered in the planting hole.  Finish it off with a 2-3 inch layer of wood mulch. Native plants and rock garden plants prefer rock mulch, so adjust accordingly.

Scissors to Score or Cut Plant Roots
A Bit More Soil is Needed, then 2-3" Mulch

Thursday, May 15, 2014

Plant Preparation Pointers

Spring shopping for gardeners is like the shoe shopping obsessed woman (or man). You shop often and usually buy. And not that there's anything wrong with either or both!  But as you shop and cart home the goods waiting for the right time to plant (usually in-between rain or snow storms) AND when the soil has dried out, stop and read this post so the plants will live long, happy lives or for just a couple of months for your summer viewing pleasure. 

There are guidelines for plant care before they go in the ground. You are no doubt shopping at box stores and local garden centers (please do, support the home-owned shop keeper). Most retailers have plants on shelves inside and outside for sale. For the most part, plants that have been growing outside are fine to take home and plant right away, in other words, no waiting. These plants have been acclimated or the term gardeners say is "hardened off."  Because of their time outdoors, they are used to the sun (or shade, depending on the plant type), winds and nights. 

Plants that you purchase from inside the store need some special handling at your house. They need to toughened up to handle the elements just like the plants that were outside. Once home, put them outside for a few days in a protected, shady site for a couple of hours, then move them indoors or in to a garage or shed at night. Increase the time and sun exposure each day. After about 5 to 7 days they are ready to be planted. After day 4 or so, you can leave them outside all night, provided the temperatures are in the mid-50s.

BUT, (there's always more), wait and plant most everything until the nights are consistently above 55 degrees. This is especially important for warm-season vegetables like peppers, eggplant and tomatoes. Wait on okra until nights are closer to 60 degrees. This ensures that they won't be cold affected so growth stops then extra weeks are needed for the plant to catch up (some never do). If you purchased cool loving annuals like violas or pansies or cool veggie starts like lettuce or broccoli, they can be planted with nights in the high 40s and above. 

BUT, you can always cheat cold temperatures by using row covers or walls of water to keep warm-season plants toasty at night. It's a good idea to keep covers close on hand in case we have some more cold-weather events, through at least mid-June.

"Hardening off herbs"

Perennials and Shrubs "Hardening Off'