The
bain of growing carrots in my garden has always been the Carrot (rust)
Fly. From late summer and through the
winter storing, my carrots had suffered the brown holes and bruised markings
from the maggots of the carrot fly. The
damage would get worse as the season progressed and eventually these number 3
carrots would be totally unusable.
Over the many years I’d tried a number of
things to alleviate the problem. In the
‘80’s I tried some polyester row cover.
It was too light and tore easily.
I then went to wooden frame panels with window screen vinyl. That started out better but soon I had aphid
buildups with no way for the ladybugs to get at them. I had to abandon these frames.
Another year I’d heard if one had wild
carrot growing nearby, the carrot fly would be attracted to that instead of
your carrots. I even brought one wild
carrot plant (free of soil) over the USA border with me from just a few miles
away. That didn’t work either.
For
several years I just didn’t grow carrots.
When I finally started back up I did quite well for the first couple of
years and then it all came back. I tried
different landscape fabrics between the rows.
And heavy leaf mulches. Nope.
Finally,
about five years ago, my son TOG was talking with a fellow grower at the local
farmer’s market. He asked what they did
(organically) for Carrot Fly. The fellow
said: “Oh, you don’t know?” and then
explained they always rotate their carrots in the beds between their long hoop
houses. It turns out the fly can’t fly
higher than 2 feet and they set up a barrier at the ends of the beds that are sandwiched between the hoop houses, blocking the access to the flies.
The
barrier can be made of anything: plywood, row cover polyester, screening, black
or clear plastic. It just has to
physically block the way for the flies.
And
so I built my first four Carrot Frames to surround my carrot beds. Made of ripped 2 X 4’s and 2 X 2’s and
stapled on old pieces of clear greenhouse plastic, I’ve surrounded my carrot
beds and have had good success for three years.
Until last year.
Last year had a few extra variables. In the rotation, my carrots follow the
greenhouse. That means every other year
the carrot frames must butt onto my new, larger greenhouse. And I need to be able to open the northern
doors of the greenhouse for ventilation which then open into the carrot beds. I had constructed a screen door for the
greenhouse that was 3 feet high but somehow the flies still got in.
I
did have one side of my carrot frames that was only 2.5 feet high plus I wasn’t as
careful with anchoring the plastic at the bottom of the frames. Perhaps they went over or under the
plastic? Also, I now till old leaves
into the bed before planting. Could I
have used leaves that had been sitting on the previous carrot bed all winter
that contained eggs or larvae that infiltrated the new bed?
This year I’ve
battened down the hatches (of flies).
The frames are not next to the greenhouse and I raised my one shorter
frame to 3.5 feet like the rest. I’ve
weighted down the 6 inch plastic skirts on the paths and on the surrounding
lawn. I made sure I had virgin, aged
leaves for digging into the bed. (Remember, those leaves tilled in increased my
poundage by 50%).
For the winter and spring, I store my carrot frames
against the back fence. To set up I just
wash them, screw them together in their corners and wrap and staple the extra
plastic at the corners. To access the
beds, I step over the frames using two 5-gallon pails as stile steps. For weeding and maintenance and reaching the
outer half of the beds, since I only have one centre path, I have a nice,
portable, plank “bed bridge’ that spans a bed so I can get at all of the two 50
square foot beds without stepping in them.
This year I was surprised with
the poorer germination of my carrot seed.
This June was exceptionally cool and I may have covered the furrows with
a bit too much sifted soil. It wasn’t
the older seed since I did some rows with my brand-new seed with the same
result. Thankfully, I got enough growing
to fill most of the rows. Although it is
nice to have the option of thinning the weaker seedlings out – just not this
year.
TOG uses a set of hoops with some polyester row / bed cover to cover
his carrot beds to keep the fly out. It seems
to work for him. I’m hoping this year’s
changes will solve last year’s glitch.
There’s nothing like bright, clear, clean carrots fresh from the garden
all winter until April.
Happy Gardening.