Peat pellets and parsnips and carrots

Personally I've only used those pellet things once and didn't get on with them as I found they dried out very quickly so surprised you've found the opposite but it was years ago so perhaps I've misremembered. That said, I don't see how they'd work for root veg as they're very small and don't have much depth. By the time you see a shoot the tap root would be out the bottom of the pellet and it wouldn't work at all unless I've totally musunderstood.

I've had very mixed results with them in the past. One time worked perfectly another they were green on top, then another complete failure.
I just can't do root veg it's a big struggle I can't be out there to water it 3, 4 or 5 times a day. It seemed so easy in the UK

How do you water your tomatoes?
I wouldn't bother with pots. You could try chitting your parsnips or sow under a plank of wood?
Make sure the ground has been well watered, sow in a drill and put a plank of wood on the top to stop the top drying out. Check it everyday until they have germinated.

Just a thought Lisa, do you have access to sand & would that hold moisture better than soil? Carrots & Parsnips can both be grown in sand. As can Tomatoes for that matter.

Me too, but not used them recently. I find that pots suit me best for raising plants. Easy to knock-out for potting on, or planting, with next to zero root disturbance, easy to water, can be stood on capillary matting for "automated" watering ...

I do like, now, to start seedlings off in 1" cell modules and then pot-up, as I found putting seedlings straight into, say, 9cm pots meant I lost some (probably due to over watering)

I much prefer to start seeds off in a small, shallow, seed tray (I use 1/4 size seed trays, but also some "pans" (shallow pots) which are 4" or 5" / 10 - 12cm diameter (rather than sowing in modules). Easier to get moisture consistent in the larger mass of seed compost in the seed tray than each and every small module cell, and takes up less space in the propagator. But I do then have to spend the time pricking out.

Places I've visited in Spain had "grey" water supply, for irrigation, in addition to drinking water. Only came on at certain times / days of the week I think. Do you have the benefit of that?

If it was me I would want some sort of irrigation system to get the water to the plants in sufficient quantity - e.g. leaky hose along the rows - and I would mulch over the top of leaky hose (and soil ) to help keep the moisture in, and the baking sun out.

I do have irrigation, put that in place last year. Big investment but helps so much. Still though it's the desert part here, it's ridiculous. I will soak and 2 hours later it's dry, very dry.
I tend to have the irrigation on in ,the evening, so soak the peppers, tomatoes etc. and they soak it up for the following day
Think I will try the plank thing, should help especially this time of year before it gets too hot. I have baby carrots in pots and doing well.
I might have a go as have some pellets left from last year. Been sent a load of free seed so nothing to loose really.

I have found I start everything of in cell trays, I am useless at thinning so it makes me space properly from the beginning and I can give the spare not quite as healthy plants away.

Underground, or just on the surface? A thorough watering should soak in and be available to the roots, even if the surface is like dust ... that will work better if there is organic material incorporated into the soil which can hold the water. Peat, Manure, Newspaper ...

When I plant out I make the planting holes first, then fill with water and let that drain into the soil, then plant. My thinking is that that means that the soil under the plant is nice and wet, so the roots grow down look for it. That moisture (here at least!!) lasts a couple of weeks and gets the plant going. If the plants are encouraged to grow roots downwards they are not at risk in the way that plants with surface roots are. Watering "little and often" encourages surface roots ('coz that's where the water is ) which then suffer when the surface dries out.

Perhaps try watering one section for twice as long, one evening, and see if it stays moist (6" down) for longer?