If it has worked for years you must be spacing things okay. But if your carrots never develop to a good size or shape you should try thinning....and do it early in their growth. If you leave them about 1 inch apart at the first thinning you can harvest every other one for baby carrots and leave the rest 2 inches apart for later harvest at full size. In nature the strong may survive, but they take alot longer to grow while competing with the ones who later die. You can "help" your veggies grow faster by getting rid of the competition early in the growing season. I like dirtbert's idea of a little experiment. Try different spacings and see what works best. Yes, you can pull out the extras, it is okay. Hopefully, you don't have trouble destroying the weeds. They are also living things, but they gotta go, too. FWIW: I shared a garden plot for awhile with someone who said I was "playing God" whenever I went in and thinned plants. But she let me do it, just didn't watch. Are you sure DH isn't already helping your garden with a bit of thinning when you aren't watching?

Carolyn I'm not sure I've seen any pictures of leaf miner damage with only straight lines, but the link below shows some straight lines in the overall pattern. That may be a banana leaf, though I'm unsure about it. The picture is of a leaf miner found in Costa Rica, but with more than 400 varieties, there may be a few who do make straight lines. From this site: Larvae hatched from insect eggs burrow into the leaf and travel within the leaf, feeding and burrowing. The larva or pupa may be visible inside the leaf when held up to a light. The burrowed areas may appear as a spot, blister or as a straight or twisting line. Areas of the leaf may die and dry up. Once feeding has been completed, white cocoons may be visible on the underside of the leaf (as with Apple Leaf Miner) or the larvae may fall to the ground to pupate within the leaf litter. This paper describes the various "mines" of leafminers as serpentine, straight, or blotched. That's why I wondered where isis is or what crops are grown nearby. Here is a link that might be useful:

below are some suggestions for early tomatoes in So Cal from Gary Ibsen Alaska Black Plum Black Prince Blondkopfchen Carmello Dad's Barber Paste Druzba Fireworks Flamme God Love Green Grape Green Zebra Jaune Coure de Pigeon Manitoba Marmande Moonglow Northern Lights Purple Russian Rose San Francisco Fog Sisters These are seed I have that are for for tomatoes that can handle cool growing conditions either at end of summer season into fall or as early plantings in So Calif Allicante 70 Days Ind C Red Golf Ball Full Bodied old time taste Anna Russian 70 days Ind CJuicy Pinkish Red Heart to 1 lbAzoychka 65 days Ind CHYellow 3" 7-8 oz Juicy sweet rich touch of acid Black Ethiopian 81 days Ind CH 5oz sweet rich and tangy Plum heavy production Black Krim 75+ days Ind CH 10-12 oz Rich Sweet reddish brown Black Pear 80 days Ind C Plentiful yield of 6-8 oz sweet well balanced flavor Black Plum 82 days Ind C Deep Mahogany elongated Plum rich sweet and tart Black Prince 70 days Ind C6-8 oz rich intense tpmatoey juicy fruits Russian Black 80 days Ind C 4 0z sweet balanced complex flavor Black Zebra 85 Ind CH Box Car Willie 80 Ind CH BuckbeeÂs New 50 Day Ind Camp Joy 80 CCHH IndCherry Carmello 75 Ind CCHH Red Salad Ceylon 70 Ind C Red mini-beef Crazy 55 Ind CH Cherry Dona 75 Ind CCHH Red French Salad Eva Purple Ball 68 Ind CH German Pink Purple 2" 6-8 oz Fireworks 60 Ind CCHH 2 ½ " 8-12 0z Hezou 80 Ind China 2" Illini Star 72 Ind Red 6-8 oz Jaune Flammee 70 Ind C2-3 oz orange globe Kelloggs Breakfast 78 Ind CH Orange Beef Lida Ukrainian 75 Ind C Lime Green Salad 52 Det CH 3 oz luscious tangy taste Malinowski 75 Ind C Polish Lots of red round 6-8 0z delicious fruit MariannaÂs Peace 80 CCHH Czechoslovakian Dense RichTomatoey flavor 16 0z Moskovich 60 S-Det CC 4-6 0z luscious rich taste Mule Team 80 Ind CCHH8-12 oz Mildly sweet  bears till frost Nyagous 76 Ind 6 oz C Russian Black Mahogany with sweet, complex fruit flavors Omars Lebanese 80 Ind CLarge Pink Beefsteak Paul Robeson 74 Ind CCH luscious, earthy, exotic with good balance Prudens Purple 75 Ind CHPurple Pink with excellent flavor like Brandywine Riesentraube 78 Ind C E Germany lots of pointed sweet grapes Rose 78 Ind CH Amish 3" meaty luscious taste Sisters 82 Ind CH Pot leaf 4" delicious pink beef Slava 65 Ind C Red 2"Delicious from Czech Republic St Pierre 84 Ind CH French Red thin skinned with a fine, sweet flavor prod up to frost Stupice 52 Ind C Czech sweet 2" deep red globes cold-tolerant Standard Early SunsetÂs Red Horizon 72 Ind CCHH Russian 4" delicious tomatoey in to November Super Snow White 75 Ind CVery sweet 2 oz Ivory ping pong size great for salads Thessaloniki 80 Ind CH Greek exceptional yields of 8oz wonderfully rich globes Tommy Toe 70 Ind Bright Red 1" cherry with excellent juicy flavor

It is a fungus stem rot commonly caused by one of 3 or 4 various soil-borne fungi. Probably pythium in this case but no way to know for sure without culturing it. See article linked below. The original problem/cause was using soil/dirt/sand in the container rather than a soil-less mix. That is never recommended as it is not sterile, already infected, and creates the perfect conditions for the fungi to multiply and infect the plant. It is then further compounded by way over-watering poorly draining soil. The roots become infected and it progresses up the stem to slightly above the soil line and into the circulatory system of the entire plant. Saving the plant is very unlikely once the symptoms develop to this degree. Sorry. Dave http://plantdiseasehandbook.tamu.edu/problems-treatments/problems-affecting-multiple-crops/stem-and-root-rot/