First early vs maincrop potatoes
Updated: October 2026
Potatoes on a seed packet covers three calendars. A first early can be out of the ground by July, while a maincrop is still filling and will sit there until autumn. The class sets the date, the space, how long the plants face blight weather, and whether the flesh is waxy or floury. This page is that choice. It does not rank a pack. The eleven amazon.co.uk listings are on our [seed potatoes](/hub/root-vegetables/seed-potatoes) comparison, and the named pick comes after you know which calendar you want. We did not run a variety trial. Shelf prices are from 15 October 2026.
Potatoes on a seed packet covers three calendars. A first early can be out of the ground by July, while a maincrop is still filling and will sit there until autumn.
Potatoes on a seed packet covers three calendars. A first early can be out of the ground by July, while a maincrop is still filling and will sit there until autumn. The class sets the date, the space, how long the plants face blight weather, and whether the flesh is waxy or floury. This page is that choice. It does not rank a pack. The eleven amazon.co.uk listings are on our seed potatoes comparison, and the named pick comes after you know which calendar you want. We did not run a variety trial. Shelf prices are from 15 October 2026.
Our top picks
| Badge | Product | Crop type | Kitchen use | Variety | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Carbeth Plants Carbeth 3 kg three-variety mix | Early and second early (seller) | Firm; boil, roast or salads (seller) | Maris Peer, Nicola, Pentland Javelin | 9.4 | about £14.99 | View offer |
| Best value |  Carbeth Plants Carbeth Maris Piper 11 tubers | Maincrop | Floury; roast, bake, mash, chips (seller) | Maris Piper | 8.8 | about £10.99 | View offer |
| Alternative |  Carbeth Plants Carbeth Pentland Javelin 11 tubers | First early (seller) | Seller: white skin, white flesh. High yield is a seller claim | Pentland Javelin | 8.6 | about £10.99 | View offer |
On this page
Three crop classes
The RHS splits the year into first earlies, second earlies and maincrops. Earlies can be ready in as little as 12 weeks. Maincrops stay in until late summer or autumn. The tubers are larger, and they are the ones you can store. Lift first earlies in June and July, second earlies in July and August, and maincrops from late August into October.
Week counts are guides, and the sources do not agree on a single number. This page keeps the RHS months as the default and does not average those bands into a new figure. Swift is sold as a first early that can be ready in as little as eight weeks. Arran Pilot’s seller says plant in January or February for a May harvest. Both are seller claims. They sit ahead of the RHS June to July lift for first earlies.
Waxy new potatoes or floury maincrops
Floury, high-starch potatoes such as Maris Piper break down for mash, roast potatoes and chips. Waxy potatoes hold a slice, which is what you want in a salad or a simply boiled new potato. Charlotte sits with the waxy salads. Maris Piper sits with the floury maincrops. In this set, Maris Piper is the named maincrop, and Charlotte is sold as a waxy second early. That is the contrast, not a ranking of every bag.
Pentland Javelin, Arran Pilot and Swift are sold as first earlies. International Kidney is sold as a waxy first early. The RHS plant page says the variety was traditionally an early maincrop and is usually grown as a new potato or a second early. Golden Wonder is sold as a dry, floury late maincrop. The 3 kg mix is sold as early and second early: Maris Peer, Nicola and Pentland Javelin. The Christmas mix is an autumn planting, not a maincrop you store from a spring sowing.
Blight and a small plot
Late blight is the main potato disease in Great Britain, on AHDB’s account. The RHS says it is less likely to affect earlies because they are often out of the ground before the worst weather. Earlies are not resistant merely because they are early. What you gain is time: you lift before the long late-summer window that a maincrop has to survive. The RHS blight feature says no pesticide is available to UK gardeners. Sarpo is not in this set.
Maincrops want the wider RHS spacing, about 37 cm in the row and 75 cm between rows, and they occupy that ground until autumn. The figures, and how to earth up, are on the how to plant seed potatoes page. A small garden that plants only maincrops gives up the bed for the whole season and still faces the longer blight window.
Which to plant this year
Choose a first or second early when you want new potatoes by July and the bed free afterwards, or when the plot is a patio. Choose a maincrop when you want larger, floury tubers you can store, and you can keep the plants in the ground into autumn. In this set that maincrop choice is a potato such as Maris Piper. The early choice is a potato such as Pentland Javelin, Charlotte or the named 3 kg mix. It is not a single winner across both jobs.
If you want salad potatoes in July, do not sow a late maincrop and hope it behaves like a new potato. If you want chips in autumn from your own store, an eight-week Swift claim will not fill a sack. After the class is settled, use best seed potatoes to match a pack, and leave the Christmas mix out of this decision.
Common questions
What is a first early, a second early and a maincrop?
A first early is the quick new potato, lifted in June and July on the RHS calendar. A second early follows in July and August. A maincrop stays until late August through October, with larger tubers you can store. Treat weeks as guides and keep the RHS months as the default.
Which is more exposed to blight?
Maincrops, because they are still in the ground in late summer, when wet weather does the damage. The RHS says blight is less likely to affect earlies. Earlies are not blight-proof. They are often lifted first. The RHS says gardeners have no pesticide for it.
Which is waxy and which is floury?
Waxy potatoes, such as Charlotte, hold together for salads and boiling. Floury potatoes, such as Maris Piper, suit chips, roast potatoes and mash. Golden Wonder is sold as dry and floury. International Kidney is sold as waxy. Texture is a kitchen fact. It does not override the calendar.
Why do sources disagree about International Kidney?
The seller calls it a first early. The RHS plant page says it was traditionally an early maincrop and is usually grown as a new potato or a second early. It is a Jersey Royal only when grown in Jersey, which this mainland bag is not.
Can I grow a maincrop in a bag?
You can try, if the container is large and you accept a smaller crop than a row. Earlies suit bags better because the plants are smaller and they finish sooner. Do not use a maincrop bag as a way to dodge blight. The plants are still out in late summer.
Related pages
Sources
Public UK sources, checked with the amazon.co.uk listings of 15 October 2026. Shelf prices and star lines are the figures in the display file. This page did not visit a garden centre.
- GOV.UK: Seed Potato Classification Scheme (retrieved 15 October 2026)
- Seed Potatoes (England) Regulations 2015 (retrieved 15 October 2026)
- SASA: Seed and ware potatoes classification (retrieved 15 October 2026)
- DAERA: Seed potatoes (retrieved 15 October 2026)
- GOV.UK: Farm-saved seed (retrieved 15 October 2026)
- RHS: How to grow potatoes (retrieved 15 October 2026)
- RHS: Potato blight (retrieved 15 October 2026)
- Potato Council: Growing healthy seed potatoes (retrieved 15 October 2026)