Blemishes on the Road to Ripe and
Happiness is a perfectly ripe and juicy tomato however;
many of those that I grow reach the table blemished by their journey
to maturity. It is after all, a long trip from tiny seed to full
ripeness – one filled with stresses that can leave marks and
The earliest blemish begins in the flower when nighttime
temperatures drift below 58F and pollination is less than perfect.
Catfaces – those abnormal formations on the blossom end of
the fruit are the result. If you are not growing organically, excesses
of nitrogen and/or pesticides can also cause catfaces. My Oregon
Spring Bush tomatoes produced several catfaced fruits this year
thanks to those 40F nights in March – but they are delicious
tasting in spite of their looks.
The other blemish commonly found on the blossom end
can happen any time during growth and maturity of the fruit. Blossom
endrot is not a rot at all, but damage caused by uneven watering
or periods of dryness. Tomatoes grown in calcium poor soils are
particularly prone to endrot however; proper and adequate watering
is the easiest solution. I have an Oregon Spring Bush tomato growing
in a large pot on the back porch and discovered how easy it is to
get endrot in potted tomatoes – the daily water demands in
summer are hard to meet.
There is another water associated blemish common to
tomatoes, splitting fruit. Splitting in the skin occurs when the
contents take in excess water and swell up. The water can be taken
in through the roots or be absorbed through the skin. Overhead watering
will guarantee split fruits, as will summer rains. The fruit will
also split if the plants are over watered – so moderate, even
watering and protection from rain will eliminate most splitting.
Hard water can also cause tomato blemishes. Pea sized
and larger hail can cause serious damage to both the fruits and
plants. It doesn’t happen often here, but one summer hailstorm
can give you a blemished harvest. I try to get row covers tossed
over the growing beds to cushion the impact, but am often not there
Too much water, too little water and water that is
too hard can all damage tomatoes, as can too much sunshine. Yup
they get sunburns, or sunscald, and it doesn’t take long.
Any die off in the shading foliage and the fruits are susceptible.
To reduce sunscald reduce vine pruning in the summertime. I got
sunscald this month when the row cover I was using as a shade cloth
blew off one afternoon. We’ll eat them anyway, even though
the sunburned spots will not ripen.
The last kind of cosmetic damage that I get comes
from sharing my fruit with other garden dwellers – mice. A
day or two before reaching perfect vine ripeness they are mouse
ready. Sometimes I can eliminate the mice, sometimes I just harvest
a day or two earlier.
So, even if your tomatoes have survived curly top,
fusarium wilt, root knot nemetodes, bacterial spot, fungal diseases
and the other fatal maladies on the road to sweet and juicy, you
may still end up with blemished fruit. Fortunately the cause of
most blemishes can be avoided with proper timing and cultivation,
and if not you still have tomatoes with character on the table.
Till next time,
Darrol Shillingburg – June 2007
Doña Ana Extension Master Gardener