AutoPot Tray2Grow System: Gravity-Fed Watering for Seed Trays and Planters

The AutoPot Tray2Grow is a watering tray that takes the job of feeding plants off your hands without using any power. You stand it on a flat, level surface, connect it by pipe to a tank raised above it, and the AQUAvalve5 lets water and nutrients into the tray only as your plants use them. There are no pumps, timers or electricity involved¹. The maker, AutoPot, describes its systems as 100% power-free, gravity-fed and regulated by what the plants drink rather than by a clock².

The tray measures 111.5cm long, 41cm wide and 9.5cm deep, and it holds up to four standard seed trays at once¹. It can also carry small pots, grow bags or a single large fabric planter of up to 107.5 litres, all fed from one watering point³. That range is what makes it useful to an ordinary household: the same tray can raise a batch of seedlings in spring and then water a tomato plant in a grow bag through the summer.

This page sets out what the system is, what arrives in the box, how to set it up level and connected to a tank, which feeding method suits which container, and how the valve prevents overwatering. It also covers the larger planter, the parts sold separately, and what UK buyers should know about ordering, because most Tray2Grow items are bought to order and lead times can be long¹.

What the Tray2Grow is and what it suits

The Tray2Grow is a modular tray and lid that acts as a shallow reservoir. The lid holds your growing setup above the water line, and an AQUAvalve keeps the reservoir topped up automatically, so plants draw moisture upwards only when they need it³. The maker's tray systems are built to irrigate several pots in a single tray and lid assembly, all fed by one AQUAvalve⁴.

Because nothing is pumped, the system does not depend on mains electricity or on pressurised water⁵. That matters in a greenhouse or shed with no power supply, and it matters in a power cut, when a pump-fed irrigation system would stop. The maker says AutoPot systems can reduce water and nutrient usage by up to 50%², and describes tray systems as growing power-free "with not a drop of water wasted"⁴.

What it suits, in practice:

• Propagation and nursery work: seed trays, small pots and microgreen trays, watered from below³.
• Grow bags and fabric planters: fed through capillary spikes pushed into the base³.
• One large plant or several in one container: the Tray2Grow Planter holds 107.5 litres and fits onto the tray⁷.
• Taller plants: guide holes on each side take garden canes or trellising¹.

It is not a complete kit for every situation. The capillary matting and root control sheet are listed as sold separately on the seed tray page⁸, and the matting page confirms the tray, lid, seed trays and root control sheets are sold separately from the mat⁶. Check what your chosen bundle includes before you order.

Size, capacity and specifications

The tray's dimensions decide where it will go: it needs a bench or floor run at least 111.5cm long and 41cm wide, with 9.5cm of depth for the tray itself¹. The Slim Kit lists the same footprint in millimetres, 1115mm by 410mm by 95mm⁹.

The full system also includes four 20 litre fabric FlexiPots¹⁰, so a household buying it can start with four individual plants rather than one large planter. The seed trays are described as durable enough for repeated use in grow rooms and nurseries⁸, and the planter is described as reusable and suitable for long-term indoor or greenhouse use⁷.

What comes in the box

The full Tray2Grow System is the most complete option, and the retailer's contents list is long. It includes the tray and lid, one AQUAvalve5, grommets, pipe, filters, an in-line tap, an overflow grommet, three circular spirit levels, ten capillary spikes, capillary matting, a root control sheet, four seed trays and a roll of slug-repellent copper tape¹. The same listing also names four 20 litre fabric FlexiPots, four PotSock rounds, two 6mm inline taps, four 6mm tee pieces, two 6mm cross connectors and a 6mm golf filter¹⁰.

The smaller Slim Kit strips this back. It contains one Tray2Grow Slim Tray and Lid, one AQUAvalve5, two 9mm grommets, 1m of 9mm pipe, a 16 to 9mm click-fit filter, a 9mm golf filter, a 9mm in-line tap, a 9mm tee connector, a 6mm overflow grommet, three circular spirit levels, capillary matting and a root control sheet⁵. If you already own a tray and lid, they can be bought on their own as a pair³.

Setting it up level and connected to a gravity-fed tank

Level is the first instruction in every set of setup steps, and it is the one that decides whether the valve works. Place the tray on a flat, level surface and check it with the built-in spirit levels¹. Three inset spirit levels are built into the tray to help you get it perfectly level¹. The Slim Kit repeats the step: position the tray on a level surface using the built-in spirit levels⁹.

Then connect the water supply. The retailer's sequence is to install the AQUAvalve and connect it using the supplied pipework and filters, choose your feeding method, link the tray to a gravity-fed water or nutrient tank, and load the plants, letting the system regulate watering automatically¹. The tank must sit above the tray: the maker says to elevate your reservoir or water butt 150cm above the lowest AQUAvalve in the system to have ample gravity feed². A retailer's greenhouse irrigation listing puts it more simply, advising that the reservoir sits slightly higher than the trays to allow proper gravity-fed flow¹¹.

If you are adding the tray to an existing AutoPot system, the 150cm figure applies to the lowest AQUAvalve in the whole system, not just the new tray². Keep that in mind before you site a second tray lower than the first.

Feeding methods: matting, spikes or bottom-fed containers

The Tray2Grow can feed plants in more than one way, and the right choice depends on what you are growing. The retailer lists capillary matting, spikes or bottom-fed containers as the options¹, and the tray and lid page splits it into capillary matting with root control for seed trays and small pots, or capillary spikes for grow bags and fabric planters³.

The matting method is the one to use for propagation. Lay the mat flat inside the tray and tuck it neatly into the side channels, place a root control sheet on top to stop roots growing into the mat, then stand seed trays, micro herb trays or bottom-perforated pots above it⁶. The retailer says the matting allows multiple trays or containers to be fed at once, making it ideal for propagation, microgreens and high-density early-stage growing⁶. The seed tray itself has a perforated base so water and nutrient solution are drawn up from below, giving steady, even moisture without overhead watering⁸.

For grow bags, remove the spikes and use the matting if you are feeding seed trays or smaller pots, or fit the spikes to irrigate directly through the base of the bag¹. The spike with capillary lace is designed to deliver water and nutrients directly into grow bags, and is listed as compatible with Tray2Grow systems, fabric or plastic grow bags, planters and large containers with base access, and propagation and vegetative feeding setups¹².

How the AQUAvalve5 stops overwatering

The AQUAvalve5 is the part that makes the system automatic without a timer. The retailer says it delivers water only when plants need it, preventing overwatering¹. The tray acts as a shallow reservoir that the valve fills and maintains, and the lid holds the growing setup above the water level so plants draw moisture upwards only when required³. The Slim Kit listing adds that the valve maintains consistent moisture levels while preserving a vital air gap in the root zone⁵.

That air gap is the point. The retailer describes the root zone design as maintaining an air gap to improve oxygen availability¹, and the tray and lid page says moisture delivered from below encourages strong root development while maintaining excellent oxygen availability in the root zone³. Roots are not left sitting in saturated compost; they take what they need and the valve tops up the tray as the level falls.

The maker's guidance adds a practical note for anyone feeding by hand as well: root activity is generally more noticeable in the early stage of plant growth and slows during the flowering and fruiting stages¹³. That is a reason to check young plants more often and to expect the tray to draw less later in the season, not a reason to change the setup.

Growing larger plants: planters, grow bags and canes

For a single large plant, or several in one container, the Tray2Grow Planter is the matching option. It is a fabric planter designed to integrate with the Tray2Grow tray, and it fits onto the tray¹⁴. It measures 93cm by 33cm by 35cm and holds 107.5 litres, which the retailer describes as ideal for large plants or multiple plants in one container⁷. Place it centrally on the tray⁷.

The planter uses breathable fabric construction with bottom-fed irrigation, working with AQUAvalve-controlled watering¹⁴. It takes soil, coco or blended substrates¹⁴, and the retailer describes it as reusable and durable, suitable for long-term indoor or greenhouse use⁷. The tray itself supports AutoPot framed fabric planters up to 107.5 litres¹, so check the footprint of any other planter before standing it on the tray.

For grow bags, the capillary spikes are the route. They pierce the underside of the bag and deliver water directly into the substrate¹. The spike with capillary lace is listed as compatible with fabric or plastic grow bags and with planters and large containers that have base access¹².

Taller plants need support, and the tray provides for it: guide holes on each side allow the use of garden canes or trellising, making the system suitable for taller plants¹. If you are growing cordon tomatoes or climbing beans in a planter on the tray, cane them at the same time as you plant, so the roots are not disturbed later.

Ordering and lead times in the UK

Most Tray2Grow items are not held on the shelf. The retailer states that the system is purchased to order, so extended lead times will apply¹. The same note appears on the tray and lid, which also showed only three left at the time of checking³, the seed tray, which showed four left⁸, the planter¹⁴, the spike with capillary lace¹², the Slim Kit⁵ and the capillary matting, which was out of stock⁶. The full system listing showed only four left¹⁰.

What that means for planning: order before you need the tray, not the week you want to sow. The retailer does not give a delivery date on these listings, only the warning that lead times are extended¹. If timing matters, ask the retailer for a delivery estimate before ordering, and check whether the item is in stock or being made to order.

For comparison, some other garden suppliers publish firm delivery windows. Harrod Horticultural says that, stock permitting, it aims to despatch orders within 1 to 2 working days, with delivery within 3 days on UK mainland¹⁵. Rainwater Harvesting Ltd says it normally operates on a 7 to 10 day delivery from receipt of order for its systems¹⁷. Those are different suppliers and different products, but they show what a stated lead time looks like; the Tray2Grow listings give none beyond the warning.

Where the Tray2Grow fits in a household growing setup

The Tray2Grow earns its place where watering is the job that gets missed. A windowsill of seedlings, a greenhouse bench of pots or a single large planter can all be fed from one tank, with no power and no timer¹. The maker's claim of up to 50% less water and nutrient use² and the retailer's note that it saves a lot of time compared with hand-watering¹⁰ are the practical case for it.

It is one tool among several. If you are starting from scratch, our guide to growing your own vegetables sets out where to begin, and sowing seeds indoors and outdoors covers timing and depth. For a greenhouse or polytunnel bench, see polytunnels and greenhouses. If you want to grow microgreens on a windowsill, our page on how to grow microgreens indoors covers the basics, and the seed sowing equipment checklist lists what to have ready. For a powered indoor setup, indoor hydroponics explains grow tents, lights and nutrient systems, and the simple hydroponic system parts list sets out the components.

If your reason for growing is to keep food coming in uncertain times, the self-reliance section covers rainwater, off-grid power and food storage alongside growing. A gravity-fed tray that keeps working in a power cut is a small but genuine part of that picture.